Devices and methods for accessing the intradural compartment and treating intracranial hematoma

ABSTRACT

Devices and methods are described for a minimally invasive procedure offering immediate relief of brain compression and prevention of subdural hematoma re-accumulation. For example, this disclosure describes devices and methods for embolization of bleeding branch vessels of the middle meningeal artery and subdural hematoma drainage in a single endovascular intervention using multimodal catheter-based technology.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of International Patent ApplicationNo. PCT/US2021/029276, filed Apr. 27, 2021, which claims benefit fromU.S. Provisional Patent Application No. 63/016,613, filed Apr. 28, 2020,the disclosures of which are hereby incorporated by reference.

TECHNICAL FIELD

This disclosure relates to devices and methods for treating intracranialhematoma and access the intradural compartment from a trans-vascularapproach. For example, this disclosure relates to devices and methodsfor embolization of the middle meningeal artery and subdural hematomadrainage in a single endovascular intervention using multimodalcatheter-based technology.

BACKGROUND

A subdural hematoma (SDH) is a collection of blood outside the braingenerally resulting from head trauma and frequently associated withblood thinners. SDH complicates approximately 11% of mild to severe headinjuries that require hospitalization and approximately 20% of severetraumatic brain injuries. If not surgically drained, SDH may cause anincrease in the pressure inside the skull, damage the delicate braintissue, and become life-threatening. Initially, acute SDH (aSDH) aremostly formed by stiff clots, but in the subsequent days, the clotsprogressively liquefy into a viscous subacute SDH (saSDH), which tendsto perpetuate and expand into a chronic SDH (cSDH). The latter conditionis becoming a public health problem in aging populations as it isassociated with brain atrophy in elderly patients and anti-coagulationwith the use of blood thinners. Annually, there are approximately 17-20per 100000 Americans affected by cSDH. To date, cSDH remains a disablingand deadly disease, with in-hospital mortality of 16.7%, 1-yearmortality of 32%, and only 21.1% of patients admitted returning home.

The standard treatment for symptomatic SDH is surgical evacuation.Generally, cSDH are relatively thin and can be drained with two burrholes, while saSDH and aSDH are formed by viscous fluid and/or clots andtheir evacuation utilizes large bone “windows” called craniotomies.Craniotomies are used in acute-on-chronic SDH (acSDH), which affect >10%of patients with cSDH and are formed by encapsulated liquefied hematomamixed with solid subdural clots. Despite the effectiveness of initialsurgical evacuation, it has been fraught for a failure rate of up to37%. Even when treatment fails once and patients undergo a secondsurgical treatment, further recurrences are common; recurrence for cSDHcan reach as high as 46%.

Surgical evacuation is commonly combined with the introduction of drainsin the subdural space, which remain in place for 2-3 days. Although thisstrategy was reported to reduce the recurrence rate and the 6-monthmortality rate by approximately 50% when compared to surgery with nodrains, drains can lead to complications such as brain injury, furtherhemorrhage from neomembranes, infection without changing the rate ofrecurrence, and/or clinical outcome.

Open surgical intervention utilizes reversal or discontinuation ofanticoagulation and antiplatelet medications, increasing the risk ofcardiovascular perioperative risks. Craniotomies can entail generalanesthesia, which can be particularly hazardous to elderly patients withother comorbidities. The morbidity and mortality rates associated withcraniotomy for SDH continues to be high and has been reported to be ashigh as 25% and 11%, respectively.

Endovascular middle meningeal artery (MMA) embolization is an emergingendovascular procedure used to reduce postoperative recurrence.Following the injection of embolic agents, the hematoma is then slowlyreabsorbed, reducing the mass effect on the brain over a period of weeksto months. A meta-analysis of MMA embolization case series reported alower recurrence rate for cSDH after embolization compared withconventional management (2.1% vs. 27.7%, OR 087, 95% CI 0.026 to 0.292,P<0.001). MMA embolization is a promising approach for treating cSDH andpreventing recurrence in high-risk patients with aSDH, saSDH, and acSDH(i.e., coagulopathy or requiring blood thinners).

Although “Two-step” management is effective (surgical evacuation forrapid brain decompression with endovascular MMA as a preoperative orpostoperative adjunct), this strategy still carries all theaforementioned risks and discomfort of surgery and requires twodifferent procedures. This is inconvenient for patients, prolongs thelength of hospital stay and recovery time; thus, increasing healthcarecosts. A fully endovascular procedure capable of embolizing the MMA toprevent SDH expansion and evacuate SDH to provide immediate relief ofbrain compression is an urgent unmet clinical need.

An integrated endovascular approach to treat chronic SDH requiresconcurrent MMA embolization and drainage of the fluid. Based on theteachings described herein that includes the anatomy of the MMA, thelocation and viscosity of cSDH, and the strength of the arterial wall ofthe MMA and the underlying dura, MMA embolization and trans-arterialcSDH is feasible by the devices and methods herein disclosed.

An endovascular approach to evacuate acute, subacute and acute onchronic typically SDH requires catheters with lumen larger than the onesthat could accommodate the MMA. In addition, embolization of the MMA isof a lesser importance compared to cSDH. Based on the teaching heredescribed that includes the anatomy and strength of the superiorsagittal sinus, the transverse-sigmoid complex and the superior petrosalsinus, trans-venous SDH evacuation is feasible by the devices andmethods herein disclosed.

The devices and methods for trans-arterial and trans-venous access tothe intracranial compartment will enable delivery of therapeutics drugsand devices within the intracranial compartment.

SUMMARY

This disclosure describes devices and methods for accessing theintradural compartment and treating subdural hematomas. For example,this disclosure describes devices and methods for embolization of themiddle meningeal artery and chronic subdural hematoma drainage in asingle endovascular intervention using multimodal catheter-basedtechnology.

Described herein are devices and methods to navigate intracranial venoussinuses from a peripheral approach and access the intradural compartmentto evacuate subdural hematomas. Also described herein are devices andmethods for transvascular access to the supratentorial intraduralcompartment. The intradural compartment is composed of the subduralspace, the subarachnoid space with their expansions (e.g., cisterns),the brain tissue, and the brain ventricles (e.g., fluid filled cavitiesinside the brain). The supratentorial compartment is considered theintracranial space above the tentorium. The devices and methodsdisclosed herein also describe access into the epidural space from atransvascular approach.

In one aspect, this disclosure is directed to a system for drainage ofintracranial extravascular fluid, thrombus or particulate matter. Thesystem includes: (i) a suction catheter defining a first lumen andhaving a distal tip portion configured for insertion into a vascularchannel; (ii) a shaft defining a second lumen and slidably disposablewithin the first lumen, a distal end portion of the shaft having acurved shape when unconstrained and being flexible so as to have alinear shape when radially constrained within the first lumen; and (iii)a stylet slidably disposable within the second lumen and having abeveled tip configured for penetration of a wall of a middle meningealartery.

Such a system for drainage of intracranial extravascular fluid, thrombusor particulate matter may optionally include one or more of thefollowing features. In some embodiments, the system also includes systema micro-catheter slidably disposable within the first lumen and having adistal tip portion configured for insertion into a branch vessel of themiddle meningeal artery.

In another aspect, this disclosure is directed to a method fortrans-arterial drainage of a subdural hematoma of a patient. The methodincludes: (a) advancing a suction catheter within the vasculature of thepatient until a distal tip of the suction catheter is located within amiddle meningeal artery of the patient, the suction catheter defining afirst lumen; (b) advancing a shaft defining a second lumen and a styletwithin the second lumen through the first lumen of the suction catheter;(c) advancing the stylet distally beyond outlets of the first and secondlumens so that a beveled distal tip of the stylet creates a puncturethrough a wall of the middle meningeal artery and dura; (d) advancingthe shaft over the stylet and through the puncture so that a distal tipportion of the shaft takes on a natural curved shape; (e) advancing thesuction catheter through the puncture; (f) advancing the shaft with thedistal tip portion having the curved shape and the suction cathetertoward the subdural hematoma until an open distal end portion of thesuction catheter is in the subdural hematoma; and (g) draining fluidfrom the subdural hematoma using the suction catheter with vacuum andpossibly other thrombectomy enhancement methods. Such a method fordrainage of a subdural hematoma of a patient may optionally include oneor more of the following features. The method may also include: (h)advancing a micro-catheter within the first lumen until a distal tip ofthe micro-catheter is located within the middle meningeal artery; and(i) injecting an embolic material via the micro-catheter to occlude themiddle meningeal artery, which is generally performed before arterialperforation. In some embodiments, the method may also includewithdrawing the suction catheter, shaft, and stylet from extendingthrough the puncture; and delivering a plug, coil or particles throughthe first lumen to block the puncture.

The devices and methods described herein provide access to theintracranial compartment enabling the permanent or temporary delivery oftherapeutics and devices and performance of multiple interventions andcan include features to: a) penetrate the dura to remain in the subduralspace; 2) penetrate the dura to transverse the subdural space intosubarachnoid space, the brain tissue and brain ventricles.

In another aspect, this disclosure is directed to a method fortrans-venous drainage of a subdural hematoma of a patient. The methodincludes: (a) advancing a suction catheter within the vasculature of thepatient until a distal tip of the suction catheter is located within anintracranial vein (like a superior cerebral vein) or dural venous sinus,the suction catheter defining a first lumen; (b) advancing a shaftdefining a second lumen and a stylet within the second lumen through thefirst lumen of the suction catheter; (c) advancing the stylet distallybeyond outlets of the first and second lumens so that a beveled distaltip of the stylet creates a puncture through a wall of the vein and/orsinus; (d) advancing the shaft over the stylet and through the punctureso that a distal tip portion of the shaft takes on a natural curvedshape; (e) advancing the suction catheter through the puncture; (f)advancing the shaft with the distal tip portion having the curved shapeand the suction catheter toward the subdural hematoma until an opendistal end portion of the suction catheter is in the subdural hematoma;and (g) draining fluid from the subdural hematoma using the suctioncatheter.

Particular embodiments of the subject matter described in this documentcan be implemented to realize one or more of the following advantages.First, the devices and methods described herein for embolization of themiddle meningeal artery provide an effective strategy to reduce chronicsubdural hematoma recurrence after surgery and as primary treatment ofchronic subdural hematoma, especially useful in patients in whomanticoagulation or antiplatelet therapy cannot be stopped. In theendovascular procedure described herein, the middle meningeal artery isembolized to decrease the blood supply to the “leaky” membranes; and thechronic subdural hematoma is drained, reducing the mass effect to thebrain without the need of opening the skull through surgery.

Second, devices and methods described herein advantageously combinemiddle meningeal artery embolization and subdural hematoma drainageprocedures in a single minimally invasive endovascular interventionprocedure.

Third, the new techniques and apparatuses described herein circumventopen cranial surgery and all the related discomfort and complicationswhile providing immediate brain decompression and prevention of hematomarecurrence.

Fourth, because the endovascular procedure described herein does notrequire reversal or discontinuation of anticoagulation, pen-operativerisks and complications are decreased, leading to improved clinicaloutcome.

Fifth, the minimally invasive intervention described can be performedunder conscious sedation (and potentially as outpatient) and withminimal discomfort, significantly shortening hospitalization time andaccelerating the recovery time of patients.

Sixth, the devices and methods described herein advantageously uses thelarger sizes of veins and dural venous sinuses to access the intraduralcompartment closer or directly on top of the SDH or with larger borecatheters. This may be needed to drain fluid with high viscosity,ingests clots, or delivery therapeutic matter and implants that wouldotherwise not fit through the arteries of the dura.

Seventh, the devices and methods described herein provide access to theintracranial compartment enabling the performance of multipleinterventions including drainage of hematoma or other fluid collections,drug and cell delivery, implantation of electrodes or tubes, biopsies.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention pertains. In addition to treatment ofsubdural hematomas in its liquid, gel or solid form (or a combination),the methods and materials herein described can be used in the treatmentof other intracranial collections such as epidural hematomas, cysts,hygromas, infection or any other fluid in any other location of thebody. Although methods and materials similar or equivalent to thosedescribed herein can be used to practice the invention, suitable methodsand materials are described herein. All publications, patentapplications, patents, and other references mentioned herein areincorporated by reference in their entirety. In case of conflict, thepresent specification, including definitions, will control. In addition,the materials, methods, and examples are illustrative only and notintended to be limiting.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description herein. Experimentalfindings to support embodiments are herein disclosed. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF THE DRAWINGS

FIG. 1A are computer generated images depicting areas of a human brainin which subdural hematomas commonly occur.

FIG. 1B shows a diagram of an example subdural hematoma.

FIG. 1C is an image depicting a number of example pathways of subduralhematoma drainage.

FIG. 1D is an image depicting the transverse sinus, sigmoid sinus, andsuperior petrosal sinus and a typical location of a subdural hematoma.

FIG. 2 is a schematic illustration of a subdural hematoma being formedfrom a bleeding branch vessel of the middle meningeal artery.

FIG. 3 is a schematic illustration of an example micro-catheter that isinjecting embolic material to stop the hemorrhage from the branchvessel.

FIG. 4 is a schematic illustration of an example stylet piercing aperforation in a wall of the middle meningeal artery.

FIG. 5 is a schematic illustration of an example guidewire beingadvanced through the wall perforation and toward the subdural hematoma.

FIG. 6 is a schematic illustration of an example suction catheter beingadvanced over the guidewire, through the wall perforation, and towardthe subdural hematoma.

FIG. 7 is a schematic illustration showing the distal tip portion of thesuction catheter in the subdural hematoma to drain the subduralhematoma.

FIG. 8 is a schematic illustration of the suction catheter delivering acollagen plug to occlude the wall perforation and middle meningealartery branch vessels.

FIG. 9 shows the collagen plug occluding the wall perforation and middlemeningeal artery branch vessels in an example final configuration afterremoval of the suction catheter.

FIG. 10 is a schematic illustration of another example shaft that has adistal end portion with a double “J” configuration.

FIG. 11 shows the shaft of FIG. 10 in a suction catheter.

FIG. 12 shows the shaft of FIG. 10 puncturing the wall of the middlemeningeal artery.

FIG. 13 shows the advancement of the suction catheter and shaft of FIG.12 .

FIG. 14 shows another example embodiment of a suction catheter andshaft.

FIGS. 15 and 16 show the advancement of the suction catheter and shaftof FIG. 14 .

FIG. 17 shows another example embodiment of a suction catheter andshaft. The suction catheter has a lateral opening through which theshaft is advanced.

FIG. 18 shows the advancement of the shaft of FIG. 17 .

FIG. 19 is a box plot the cutting force to penetrate the MMA and thedura of the middle cranial fossa with a needle.

FIG. 20 is a box plot representing the cutting force to penetrate theMMA and the dura underlaying the frontal and parietal bones (i.e.,convexity) with a needle.

FIG. 21 is a box plot representing the cutting force to penetrate theMMA and the dura of the frontal and parietal regions (convexity) vs themiddle cranial fossa (skull base) with a needle.

FIG. 22 is a box plot representing the cutting force to penetrate thelateral wall of the anterior, middle and posterior third of the superiorsagittal sinus with needle.

FIG. 23 is a logarithmic line chart comparing viscosity and shear ratefor multiple samples of chronic subdural hematomas from differentpatients.

FIG. 24 is a line chart comparing logarithmic flow rate of chronicsubdural hematoma fluid to catheter ID.

FIGS. 25A-25C are schematic illustrations of an embodiment of thedevice.

FIGS. 26A-26F are schematic illustrations of a subcomponent including anRF energy element to drain an SDH.

FIGS. 27A-27K are schematic illustrations of a subcomponent including ananchoring element to performate a dura, drain an SDH, and close thearteriotomy.

FIGS. 28A-28C are schematic illustrations of a catheter including twoactuators for directing the distal catheter end.

FIGS. 29A and 29B are schematic illustrations of a catheter includingone actuator for directing the distal catheter end.

FIGS. 30A-30E are schematic illustrations of a catheter including anaperture and a secondary catheter for annex wire anchoring.

FIGS. 31A-31D are schematic illustrations of a device including anintravascular ultrasound element for imaging an artery and surroundingtissues.

FIGS. 32A-32I are schematic illustrations of various embodiments of theshaft including unclogging elements.

FIG. 33A is a schematic illustration of a catheter embodiment toincrease suction force and flow.

FIG. 33B is a schematic illustration of a catheter embodiment to disruptparticulate matter plugging the distal end of the catheter.

FIGS. 34A-34E are schematic illustrations of accessing the subduralspace though the wall of the SSS and draining an SDH.

FIGS. 35A-35C are schematic illustrations of anchoring the device withan annex wire in a secondary vascular branch such as the SPS.

FIGS. 36A and 36B are schematic illustrations of a sheath including anannex that can be advanced over a wire in the SPS.

FIGS. 37A-37C are schematic illustrations of a catheter including ananchor element and protective sheath including a rail system.

FIGS. 38A-38D are schematic illustrations of a device including aballoon element connected to the shaft.

FIG. 39 is a line chart comparing the permittivity of blood and cranialtissue at different radiofrequencies.

Like reference numbers represent corresponding parts throughout.

DETAILED DESCRIPTION

The device and method here disclosed is an entirely new class ofplatform to enter the intradural compartment from a vascular lumen. Thissystem would enable trans-vascular neurosurgery including drainage ofSDH without opening the skull. A minimally invasive procedure offeringimmediate relief of brain compression and prevention of subduralhematoma re-accumulation, ideally done with a single approach andwithout the need of stopping anticoagulation, is an unmet clinical need.Accordingly, this disclosure describes devices and methods for treatingsubdural hematoma in such a fashion.

This disclosure describes devices and methods that include middlemeningeal artery embolization and subdural hematoma drainage in anendovascular intervention by a catheter-based technology fortrans-arterial hematoma drainage. The device navigates into the MMA fromperipheral arterial access and enables the delivery of embolizing agent;provides access to the subdural space from the intra-vascularcompartment; reduces blood extravasation while the passageway is patent;enables navigation within the intracranial compartment without brainperforation or damage; allows drainage of subdural collections; andfacilitates arteriotomy (e.g., perforation of the arterial wall and/ordura) closure and artery occlusion upon the removal of the cathetersystem.

This disclosure also describes devices and methods for navigation intothe dural sinuses, including the superior sagittal sinus and thesuperior petrosal sinus, from a peripheral venous approach andperforation into the subdural space for hematoma drainage. The deviceincludes trans-venous use which navigates into the dural sinus fromperipheral venous access; provides access to the subdural space from theintra-vascular compartment; prevents blood extravasation while thepassageway is patent; enables navigation within the intracranialcompartment without brain perforation or damage; allows drainage ofsubdural collections; facilitates durotomy closure upon the removal ofthe catheter system.

Referring to FIG. 1A-D, a subdural hematoma (SDH) is a type of bleedingin which a collection of blood—usually associated with a traumatic braininjury—gathers between the inner layer of the dura mater and thearachnoid mater of the meninges surrounding the brain. It usuallyresults from tears in bridging veins that cross the subdural space.Subdural hematomas may cause an increase in the pressure inside theskull, which in turn can cause compression of and damage to delicatebrain tissue. SDH are located between the brain and the dura mater(e.g., the dura) and typically facing the convexity of the cerebralhemisphere and in proximity to the vascular structures of the dura,including the MMA, the superior sagittal sinus (SSS), inferior sagittalsinus (ISS), the superior petrosal sinus (SPS), the transverse-sigmoidjunction or the transverse sinus (TS).

Distribution of SDH was computed by analyzing CT scans from 71 patientswith each case including scan at 9 different levels: 1) axial plane: 1cm from the vertex, top of corpus callosum, foramen of Monroe,mid-brain, 2) coronal plane: sphenoid wing, forum rotundum, 4^(th)ventricle, tentorial notch, and torcula. The possibilities of SDHpresence at the surface of the brain on each 2D plane were thencalculated and used to compute the probability of SDH presence along theperipheral of the 3D brain with spatial interpolation. The results areshown in FIG. 1A which is a contour map of the probability of SDHpresence at different locations of human brain in 3D isometric view(left), lateral view (top right), and superior view (bottom right). Thecolor legend bar denotes the probability on a scale from 0 to 1 in 0.1units. The units of the x- and z-axes is millimeters (mm).

FIG. 1B-D show example access routes of the devices and methodsdisclosed herein to access the subdural space and drain subduralhematomas from a trans-arterial and trans-venous route.

Referring now to FIG. 1B, the MMA 20 is typically the third branch ofthe first portion of the maxillary artery, one of the two terminalbranches of the external carotid artery. FIG. 1B is an image showing acoronal section of the head including the skull 1, brain 2, the dura 4,and with a left-sided subdural hematoma 10 and the relationship to themiddle meningeal artery (MMA 20) and superior sagittal sinus (SSS 5).

FIG. 1C is an image showing a posterolateral view of the skull 1 withthe vasculature of the dura 4. Dotted lines represents pathway of SDHdrainage through the middle meningeal artery (MMA 20), the superiorsagittal sinus (SSS 5), the inferior sagittal sinus (IPS 6), thesuperior petrosal sinus (SPS 7).

There is one MMA 20 in each side of the head. After branching off themaxillary artery in the infratemporal fossa, it runs through a bonycanal called foramen spinosum to enter the intracranial compartmentwhich can measure 0.3 cm to 2.8 cm. Upon entering the intracranialcompartment, the MMA 20 is deflected anteriorly and laterally at anangle of 60 to 120 degrees from the longitudinal axis of the foramenspinosum and runs on the epidural side of the dura 4 (between the dura 4and the skull 1).

The artery runs in a bony groove of the internal surface of the calvariawhich typically surrounds the artery in <180 degrees of itscircumference. The main trunk of the MMA 20 measures 24 mm±10 mm, andthen bifurcates into a frontal and a parietal branch. Other minorbranches are present. The mean diameter of the main trunk of the MMA 20s is 0.9 mm±0.3 mm, but it is generally larger in cases of cSDH with amean diameter of the 1.48 mm±0.48 mm.

The SSS 5 is a midline vein without valves that courses along the falxcerebri from the vicinity of the crista galli to the confluence ofsinuses at the posterior cranium. The superior sagittal sinus faces bothcerebral hemispheres for a typical length of 31 cm to 38 cm, andreceives 12 to 20 venous tributaries from each side (left and rightcerebral hemispheres). The sinus has a triangular shape with a typicalwidth of 3 mm to 18 mm and a height of 3 mm to 14 mm. The typicalcross-sectional area of the SSS 5 ranges 15 mm² to 90 mm², and the anglebetween the sinus wall and a midline typically ranges 25° to 65°. Thestructural analysis of the SSS 5 and subdural space (SDS) innon-contrasted head CTs of 100 patients undergoing surgical evacuationof SDH 10 showed that the SSS 5 has a typical width of 9.6 mm (SD 2.4),a typical height of 5.6 mm (SD 1.6), and a typical area of 34.5 mm² (SD13.8). The minimal width of the parasagittal subdural space (i.e.,between the SSS 5 medially and the SDH 10 laterally) was 5.3 mm (SD3.3), and the distance between the SSS 5 and the SDH 10 via the subduralspace was 19.8 mm (SD 14.1).

Typically, the sinus is larger closer to the confluence of the sinuseson the back of the head. At the confluence of the sinuses, the lumen ofthe SSS 5 continues into the transverse and sigmoid sinus, and thendrains into the jugular vein. The SSS 5 is surrounded by dura 4 materand separated from the brain by the arachnoid and subarachnoid spacefilled with cerebrospinal fluid. In elderly patients the brain undergoesatrophy resulting in widened spaces between the sinus and the brain. Ina cohort of 90 patients with chronic SDH 10, we found that the spacebetween the surface of the brain and the dura 4 covering the skull 1 ina parasagittal location is 1 mm to 20 mm, typically 2 mm to 8 mm. Thedistance between the SSS 5 wall and the SDH 10 ranged between 0 mm and60 mm, with >90% of the patients within 40 mm, and >75% of patientswithin 20 mm.

FIG. 1D is an image showing an oblique view of the left middle andposterior cranial fossa. The transverse sinus 11, the sigmoid sinus 12,and the superior petrosal sinus 13 are highlighted along with thetypical location of the subdural hematoma 10 is highlighted in red. Theangles between each sinus, 11, 12, and 13 are marked with black dottedlines. The angles of the trajectory for transvascular perforation fromthe junction of the three sinuses, 11, 12, and 13, is marked in graydotted arrows.

The superior petrosal sinus (SPS 13) is part of the dural venous systemthat typically receives blood from the cavernous sinus and superiorpetrosal venous complex and drains into the transverse sinus 11. The SPS13 connects with both the cavernous sinus and transverse-sigmoidjunction in 60% of cases, only laterally with the transverse-sigmoidjunction without connecting with the cavernous in 37%, and only thecavernous sinus without connecting with the transverse-sigmoid junctionin 3%. In addition, the SPS 13 is a bilateral structure. Therefore, in97% of cases it is possible to access the SPS 13 though a transjugularapproach (the transverse sinus 11 drains into the sigmoid sinus 12,which in turn continues and jugular bulb and then internal jugular veinand the skull 1 base). The sinus runs in a groove in the temporal bonecalled superior petrosal sulcus, and the tentorium cerebelli is attachedto the edges of the SPS 13. The connection of the SPS 13 to thetransverse sinus 11 or transverse-sigmoid junction occurs in the mostposterior and lateral part of the superior petrosal sulcus, and it is ananatomically strategic point for perforation (from the proximal SPS 13,transverse sinus 11 or transverse sigmoid junction) into the subduralspace to reach the cerebral convexities. The angle between the SPS 13and the transverse sinus 11 is generally 80 degrees to 120 degree in anaxial plane. The angle between the SPS 13 and the sigmoid sinus 12 istypically 30 to 80 degrees. The SPS sinus is typically 1 mm to 5 mm indiameter. Most of SDH 10 over the cerebral convexity will be accessed ifthe transvascular perforation and subdural space navigation is done atan angle of 80 degrees to 180 degrees from the longitudinal main axis ofthe SPS 13.

Referring to FIGS. 19-22 , needle penetration tests were performed andthe results displayed in box-and-whisker plots with penetration force onthe y-axes and sample identification on the x-axes. The median value isthe central line, the box encompasses the first and third quartiles, anddotted lines extend to the minimum, and maximum values respectively.

The needle penetration tests were performed through the wall of the MMA20 and dura 4 was conducted with a stainless-steel beveled needle(distal bevel 21 degrees, proximal bevel 14 degrees) with an outerdiameter of 0.014″ and with an angle of attack of 10-15 degrees. Forexample, a 20G needle with a 1¼″ length manufactured by Jelco such as anIV Catheter Radio-opaque, REF 4056, MOD11.

FIG. 19 represents the cutting force to penetrate the MMA and the duraof the middle cranial fossa with a needle.

FIG. 20 represents the cutting force to penetrate the MMA and the duraunderlaying the frontal and parietal bones (i.e., convexity) with aneedle.

FIG. 21 represents the cutting force to penetrate the MMA and the duraof the frontal and parietal regions (convexity) vs the middle cranialfossa (skull base) with a needle.

FIG. 22 represents the cutting force to penetrate the lateral wall ofthe anterior, middle and posterior third of the superior sagittal sinuswith needle.

As shown in FIGS. 19-22 , the required cutting forces to penetrate fromthe arterial lumen to the subdural space are as follows: 1) MMA 20/dura4 overall: 0.75 N (standard deviation (SD) 0.33N); 2): MMA20/Non-calcified dura 4: 0.68 N(SD 0.24N); 3) MMA 20/Calcified dura 4:1.29 N(SD 0.48N). The MMA 20/dura 4 of the middle cranial fossa requireda cutting force of 0.39N (SD 0.12N).

Penetration of MMA 20 wall and non-calcified dura 4 with same needle andan outer beveled shaft (distal bevel 23 degrees, proximal bevel 9degrees) with an outer diameter of 0.028″ required a cutting force of1.8 N to 2.2 N. Penetration of MMA 20 wall and non-calcified dura 4 withsame needle and an outer shaft as above and a non-tapered catheter withan outer diameter of 0.045″ required a cutting force of 2 N to 8 N.Penetration of MMA 20 wall and non-calcified dura 4 with same needle andan outer shaft as above and a tapered catheter (inner diameter at thetaper of 032″ to final outer diameter of 0.045″) required a cuttingforce of 1.5 N to 2.5 N.

Needle penetration test (with the needle of 20G 1¼″ Jelco IV CatheterRadio-opaque, REF 4056, MOD11) through the wall of the SSS (includingdura 4) with an angle of attack of 10-15 degrees required the followingcutting forces: 1) SSS overall: 0.57 N(SD 0.25N); 2) anterior third ofthe sinus: 0.53 N(SD 0.22N); middle third of the sinus: 0.56 N(SD0.28N); 3) posterior third of the sinus: 0.61 N(SD 0.24N). Using atri-axial telescoping perforating system formed by a needle (0.042″)mounted on a trocar (OD 0.083″) and a catheter (ID 0.088″/OD 0.106″), 6Nof force was required to perforate though the SSS into the subduralspace.

Referring to FIG. 23 , ten cSDH were collected during evacuation surgeryin ten patients and were tested on a reometer (DHR-1 Hybrid, TAInstruments) to evaluate the visocisty under different shear rates(e.g., γ=10⁻², 10⁻¹, 1, 10, 100, and 1000 s⁻¹) at 37° C. FIG. 23 is alogarithmic line chart with viscosity on the y-axis in Pa·s, and shearrate in s⁻¹ on the x-axis. A sample key is inset in the upper right anda curve fit is shown as a dashed line having a negative slope and theviscosity of water is shown as a horizontal dashed line at 10⁻³ Pa·s(labeled “water”).

A non-Newtonian shear-thinning behavior was observed. A power-law wasused to estimate (e.g., fit) the viscosity as μ=K{dot over (γ)}^(n-1),where μ is the viscosity, {dot over (γ)} is the shear rate, and K and nare material constants and equal to 0.113 Pa·s and 0.410, respectively.The fit is shown as the dashed line correlated with the sample points.

Referring to FIG. 24 , for non-Newtonia fluid going through a tube undera pressure gradient, the flow rate Q is calculated by

${Q = {\frac{\pi D^{3}}{{8/n} + 24}\left( \frac{\Delta{PD}}{4{LK}} \right)^{1/n}}},$

where D is the catheter ID, ΔP is the pressure difference between thearterial pressure at the catheter distal end and the vacuum pressure atthe promixal end, L is the catheter length. FIG. 24 is a line chartcomparing logarithmic flow rate in mL/min on the y-axis to catheter IDin inches along the x-axis. The aspirational flow rate of SDH fluid isshown as a curved line as a function of catheter ID, assuming −45 kPavacuum pressure is generated by manual pull of a syringe and thecatheter is 1.4 m in length.

From the equation, the flow rate is in proportion to D^(5.44) therefore,the ID should be selected as large as possible while maintainingcatheter access to the MMA 20. A catheter with 0.027″ ID can generate anaspirational flow rate of 18 mL/min. We found that cSDH can be aspiratedat a clinically relevant rate by a syringe though a 150 cm long catheterwith an ID 0.027″. Catheters with 0.027″ ID can be navigated into theMMA 20.

FIG. 2 is a schematic illustration of a subdural hematoma 10 beingformed from a bleeding membrane and/or branch vessel 22 of the middlemeningeal artery 20. After branching off the maxillary artery in theinfratemporal fossa, it runs through the foramen spinosum to supply thedura 4, the outer meningeal layer, and the calvaria. In cases of cSDH,the MMA 20 also supplies blood to pathological membranes responsible toexpand and perpetuate the collection.

In order to identify bleeding vessels such as the bleeding branch vessel22, an imaging procedure can be performed. For example, in someembodiments an x-ray (fluoroscopy) and/or computed tomography (CT)imaging procedure can be performed to identify bleeding vessels that arecontributing to the subdural hematoma 10. In such a case, a contrastmaterial (e.g., iodine-based contrast materials) can be injectedintravenously and used to enhance the x-ray and/or CT images.

FIG. 3 is a schematic illustration of an example micro-catheter 110 thatis injecting embolic material (e.g., liquid embolic agents, microparticles, etc.) to embolize the membranes and stop or prevent thehemorrhage from the branch vessel 22 and the membranes that the branchesirrigate. The micro-catheter 110 is advanced via a suction catheter 100that can be installed into the patient's vasculature through an accesspoints such as the femoral artery (groin) or the radial artery (wrist)or any other suitable vascular access point. Typically, the suctioncatheter 100 will be delivered into the internal maxillary arterythrough the lumen of a guide catheter (typically 5 French or 6 French,e.g., 5F or 6F) that is introduced into a sheath placed in theperipheral arterial vasculature of the patient, typically the femoraland radial artery; less commonly, the brachial artery and carotidartery.

Based on the results herein disclosed, the following designspecification can be considered a preferred embodiment: the suctioncatheter 100 has a distal OD less than or equal to 0.060″ to navigateMMA 20, and a distal ID greater than or equal to 0.020″ to drain the SDH10, a working length of greater than or equal to 125 cm to enabletransfemoral and transradial interventions. The suction catheter 100 isable to advance through a minimal curve angle of 70° without kinking toenter the intracranial compartment through the foramen spinosum. Thesuction catheter 100 has sufficient column strength to generate greaterthan 1 N forward load without kinking, ovalizing, or herniating into theparent lumen or branching artery to perforate the MMA 20/dura, andgenerates aspiration force >20 inHg without collapsing to aspirate theSDH 10 with a syringe while not collapsing or kinking at the perforationsite through the MMA 20 wall and dura.

FIG. 4 is a schematic illustration of an example stylet 130 piercing aperforation in a wall of the MMA 20 in a direction toward the subduralhematoma 10. The stylet 130 can have a beveled distal tip portion toassist with the penetration of the wall of the MMA 20. The stylet 130 isadvanced through a lumen of a shaft 120 that is, in turn, advancedthrough a lumen of the suction catheter 100.

The shaft 120 is compatible with (e.g., ID greater than) 0.014″microwires which are advanced over a wire into the MMA 20. The shaft 120ID is greater than 0.012″ to inject PVA particles sized 150-250 μm andhas a distal OD less than 0.006″ smaller than the catheter's ID to avoidthe catheter's edge to catch the dura 4. The shaft 120 includes auni-directional deflection to direct stylet towards subdural space

The stylet 130 includes a distal OD of less than 0.003″ smaller than theshaft 120 ID to avoid the shaft 120 edge catching on the dura 4. Thestylet 130 advances through the shaft 120 with a minimal curve angle of70° to enter the intracranial compartment through the foramen spinosum.The stylet 130 includes a sharp beveled needle at the distal end fortrans-arterial perforation of less than 1 N cutting forces, and aclosure device having a diameter compatible with delivery through thecatheter with a minimal curve angle of 70°. This allows the stylet 130to enter the intracranial compartment through the foramen spinosum viapushing or detaching. All subcomponents are radio-opaque (e.g., providesufficient x-ray attenuation to be visualized on conventionalfluoroscopy), or have at least one or more radio-opaque region.Alternatively, the components can include one or more fluoroscopicmarkers, such as gold, platinum, platinum iridium, tantalum, bismuth,and tungsten-filled polymers.

In some embodiments, markers are applied in the back end of theperforating elements to indicate the relative location at the front end.Markers can display rotational orientation or relative depth of eachelement of the device.

In some embodiments, the back end of the stylet 130 and shaft 120 arecoupled by an assembly that enables adjustments of the relative lengthof these elements. Examples of the assembly can include a threaded screwoperated by knob or a wheel. This assembly beneficially retracts thestylet 130 into the distal shaft 120 to prevent the beveled tip of thestylet 130 to damage, e.g., scratch and/or catch, the inner surface ofthe suction catheter 100 during advancement especially at the angulationof the foramen spinosum. This assembly exposes the cutting bevel of thestylet 130 to a set distance distal to the shaft 120 fordepth-controlled penetration.

FIG. 5 is a schematic illustration of the shaft 120 being advancedthrough the wall perforation of the MMA 20 and toward the subduralhematoma 10. The shaft 120 is advanced over the stylet 130 and has asuitably high pushability (e.g., column strength). The flexible distaltip portion of the shaft 120 has a natural, unconstrained curved shape(e.g., J-shape) so that the shaft 120 can be advanced atraumaticallytoward the subdural hematoma 10. Based on advancement of microcatheters110 with an OD of 0.040″ over a tip of a 0.014″ microwire though thesubdural space in cadaveric human heads, subdural navigation is feasibleand does not result in macroscopic brain damage, e.g., atraumatically.During advancement in the subdural space, the J or U shape is parallelto the brain surface. This decreases the risk of unwanted brainpenetration. If the advancement of the shaft 120 disposes the shaft 120between the brain surface and the SDH, the shaft 120 is rotated todirect the J or U shape towards the SDH and then advanced.

Although the shaft 120 has an unconstrained J or U shape, while thedistal tip portion of the shaft 120 is over the stylet 130, the rigidityof the stylet 130 causes the distal tip portion of the shaft 120 to bestraightened (e.g., as depicted in FIG. 4 ). In some embodiments, theshaft 120 is a coiled-wire reinforced micro-catheter. By changing therelative position of the stylet 130 over the shaft 120, the stiffnessand shape of the shaft 120 are modified.

FIG. 6 is a schematic illustration of the suction catheter 100 beingadvanced over the shaft 120, through the wall perforation of the MMA 20,and toward the subdural hematoma 10. The suction catheter 100 can be awire-reinforced tube. The suction catheter 100 will be advanced untilthe distal tip portion of the suction catheter 100, with its open port,is positioned in the subdural hematoma 10. The advancement of thecatheter 100 can be facilitated by irrigation of solution into thesubdural space. The shaft 120 and catheter 100 can be coated bylubricious substances like Teflon® or similar.

FIG. 7 is a schematic illustration showing the distal tip portion of thesuction catheter 100 positioned in the subdural hematoma 10. From here,suction can be applied using the suction catheter 100 to aspirate bloodand/or other fluids to at least partially drain the subdural hematoma10. The wire reinforcement of the suction catheter 100 can help toprevent the suction catheter 100 from collapsing while vacuum is beingapplied to aspirate the subdural hematoma 10. The applied vacuum can becontinuous, dynamic, cyclical, and pulsatile, at low and/or highfrequency. Pulsatile pressure induces clot fatigue and fracturefacilitating aspiration removal. Fluid drainage can occur spontaneouslyby a pressure gradient between the intracranial compartment and theatmosphere. Vacuum can be applied either using syringes or pump.

FIG. 8 is a schematic illustration of the suction catheter 100delivering a hemostatic element 180 (e.g., a collagen material that canbe used, for example, to cause rapid hemostasis in a puncture site, oranother type of plug material/device) to occlude the wall perforation ofthe MMA 20 and to occlude branch vessels of the MMA 20. Thereafter, thesuction catheter 100 can be withdrawn, as depicted in FIG. 9 , tocomplete the procedure described in FIGS. 2-9 for draining the subduralhematoma 10.

FIGS. 2-9 describe a platform of devices, also referred to herein as anExtra-Vascular Access Catheter (EVAC). As described above, the EVACdevices includes at least the suction catheter 100 and a perforatingelement that can be formed by the micro-catheter 110, and the shaft 120.However, two of these components could be merged into a single componentby design to achieve similar procedural steps, or more components couldbe added.

The EVAC device is a platform that provides access to the subdural spacefrom the intra-vascular compartment, prevents blood extravasation whilethe passageway is patent, enables navigation within the intracranialcompartment without brain perforation or damage, allows drainage ofsubdural collections, and ensures passageway closure (and arteryocclusion if needed) upon the removal of the EVAC device.

Referring to FIGS. 25A-25E, an embodiment of the EVAC device 2500 isshown. The EVAC device 2500 shown in FIG. 25A is, in some embodiments,the suction catheter 2510 subcomponents (e.g., a micro-catheter, shaft2520, or stylet 2530) herein described are actuated directly by hand, orat least partially by a handle assembly 2540. In one embodiment of thehandle assembly 2540, the suction catheter 2510 is attached, at an endproximal to the user, to a handle housing 2550 including a port 2560connected to a vacuum source for SDH 10 suction.

Inside the handle housing 2550 and co-axially with the suction catheter2510, the shaft 2520 is assembled at the proximal end to a slider 2570,which when operated by pushing or pulling the slider 2570 slides along aslot 2572 on the handle housing 2550 and creates corresponding co-axialtranslational movement of the shaft 2520 within the suction catheter2510. The shaft 2520 distal end is positioned relative to the suctioncatheter 2510 distal end using the slider knob 2570. The slider 2570 isrotatably tightened against the handle housing 2550 in a setscrew manner(e.g., using a setscrew, or rotated into the handle housing to freezethe shaft 2520 translation motion) to maintain the shaft 2520 positionwithin the suction catheter 2510. In some embodiments, the shaft 2520has a beveled cutting tip with a hollow lumen to dispose an atraumaticmicrowire.

The handle housing 2550 proximal end receives a stylet knob 2580 towhich the stylet 2530 is assembled. FIG. 25B shows a cross-section viewof the components of the handle assembly 2540 including the nestedassembly of the suction catheter 2510, shaft 2520, and stylet 2530. Thestylet 2530 terminates and affixes within the stylet knob 2580 at theproximal end. The stylet knob 2580 controls the relative position of thestylet 2530 through rotation driving the stylet knob 2580 into or out ofthe handle housing 2550.

A ring seal 2590 is arranged at the proximal ends of the suctioncatheter 2510 and the shaft 2520 which reduces vacuum leakage and theintroduction of air into the system. In one embodiment, each of thesuction catheter 2500, shaft 2520, and stylet 2530 has a liquid port toinfuse fluid such as saline lubrication and dilution of SDH. In analternative embodiment, these ports can also be connected to a vacuumsource to enhance SDH aspiration, such as port 2560. In variousalternative embodiments, discrete markers or rulers are labeled on theslider 2570 and/or stylet knob 2580 to indicate the relative positionsof the distal ends of the shaft 2520, the suction catheter 2500, and/orthe stylet 2530. In another embodiment, a spacer with inner threads,such as a nut, can assembled between the stylet knob 2580 and slider2570 to reduce the maximum protrusion of stylet 2530 from the shaft 2520distal end and provides a hard stop.

FIG. 25C is a transverse cross-section view of the handle assembly 2540through the handle housing 2550 and slider 2570 and perpendicular to thelongitudinal axis of the handle housing 2550, stylet 2530, and shaft2520. The rotatable connection of the slider 2570 is shown on the left.The slider 2570 is rotated until the slider 2570 contacts the handlehousing 2550 and maintains the shaft 2520 positioning with respect tothe handle housing 2550.

The EVAC device 2500 is navigated into the MMA from a peripheral accessand is used to deliver intra-arterial embolization material formicrovasculature occlusion of membranes. Then, the EVAC device 2500 isused to intentionally perforate the arterial wall, advance through thesubdural space (e.g., between the brain, the dura, and the skull), anddrain the chronic subdural hematomas (cSDH). During access, a hemostaticelement is deployed, delivered or injected across the arterialperforation and or the lumen of the MMA closing the extravascularpassageway.

It should be understood that the devices, systems, and methods describedherein are not exclusively for drainage of fluid, clots and particulatematter from the subdural space. Instead, the methods and systemsdescribed herein can be adapted to obtain safe access and drain fluidand clots in the epidural space, for example, such as for evacuation ofacute epidural hematomas, cystic fluid and pus. In these cases, thesystem can also include elements to macerate clots (e.g., rotatingelements, vibrating elements, fluid jet, etc.), disposed inside,outside, or both of the evacuation catheter. In addition, the methodsand systems described herein can be adapted to obtain access to anyintracranial target in the intradural compartment, including thesubarachnoid space, the cisterns, the brain tissue and the brainventricles.

It should be understood that the devices, systems, and methods describedherein are not exclusively for drainage of fluid or particulate matterthrough the arteries. Instead, the methods and systems described hereincan be adapted and used to obtain safe access to the subdural orepidural space and drain fluid, particulate matter and clots thoughveins, the dural venous sinuses and any other natural corridor.

It should be understood that the devices, systems, and methods describedherein can be used to obtain safe and stable transvascular access to anyextravascular space and then close the arteriotomy or venotomy site.

VARIATIONS AND OTHER EMBODIMENTS AND/OR FEATURES

In some embodiments, the shaft 120 has diathermy, electrocautery or anyother electrical feature to facilitate arterial wall penetration andentry into the subdural hematoma. Diathermy, laser and electrocauterycan also be used to cut and or coagulate the membranes surrounding thesubdural hematoma, the septations inside the hematoma, or any bleedingsource. Diathermy, laser and electrocautery can also be used to closethe transvascular passageway and the vascular lumen such as the MMA. Amonopolar or bipolar cautery can be used as a separate component orintegrated into the suction catheter 100 and/or shaft 120. In someembodiments, the shaft 120 can act as a monopolar (at least a segment ofthe shaft, generally the tip) and the shaft 120 and the catheter 100 (atleast a segment, generally at the distal end) can act as a bipolarduring coupled action.

In some embodiments, the shaft 120 or the suction catheter 100 can becoupled with thermoablation.

Referring now to FIGS. 26A-26F, in some embodiments, at least one of thepenetrating elements (stylet 2630, shaft 2620, and suction catheter2600) has radiofrequency (RF) ablation tip. RF energy can be applied torapidly increase tissue temperature to convert fluid to steam (i.e.vaporization) resulting in focal tissue disruption and void.Vaporization may result in a fenestration from the vascular lumen to theintradural compartment. This is beneficial to decrease the cutting forcefor perforation and requiring reduced column strength compared tomechanical needles including cutting edges. The resulting tissue voidwould also reduce the likelihood of edge catching along thetrans-vascular passageway. In addition, atraumatic RF needles tip wouldbe less likely to damage the shaft and suction catheter.

In some embodiments, RF energy is used to facilitate ingress into theSDH through the surrounding membranes, perforation of septationsassociated with mixed-aged SDH and chronic SDH, and to unclog theapertures of the draining tubular element (e.g. suction catheter).

In some embodiments, RF ablation energy can also be delivered by thesame or additional RF element to coagulate tissues at the penetrationsite and arterial closure if needed at the conclusion of theintervention. In some embodiment, the RF element tip includes two ormore electrodes with connecting wires extending from the distal end tothe proximal end of the RF element and connected by an electrical jointwithin a hub to a RF generator. These wires are typically made ofconductive metals such as stainless steel, copper, and silver and areinsulated with plastic layers such as PTFE or by embedding inside thewall of the shaft or the suction catheter. The electrodes areuninsulated and are made of or coated with conductive and biocompatiblemetal with high radiopacity such as stainless steel, silver, gold orplatinum. In some embodiments, one or more electrodes are connectedindividually to a RF generator to work in parallel in a monopolar mannerand share the same grounding pad. In another embodiment with twoelectrodes, one of the electrodes is connected to the RF generator whilethe other one of the electrodes is connected to the ground to work in abipolar manner. In another embodiment, a single or a plurality (>2) ofelectrodes can be assembled to the RF element and configured to work inmonopolar or bipolar manner thereof. In a bipolar system, the current ispreferentially concentrated between the two electrodes.

In some embodiments, a bipolar configuration can be obtained by anelectrode in the suction catheter and one electrode in the perforatingelement. The perforating element may acquire a shape upon emergence fromthe suction catheter to direct the tip to the arterial wall and dura.The penetrating element and the suction catheter can be concurrentlyadvanced maintaining the distance between electrodes and delivery ofcurrent to the tissue, or the perforating element can be advanced whilemaintaining the suction catheter stationary resulting in an increaseddistance between electrode with a drop in tissue disruption anddecreased likelihood of brain penetration.

In some embodiments, the electrode of the energy delivery device has oneof the following shapes: bullet, cone, truncated cone, cylinder, sphere,dome, ring, semi-annular, ellipse, bevel, and arrowhead. The shapes canbe at least partially electrically insulated for preferential currentdelivery and directional perforation. The electrically exposed area ofthe electrode is no greater than 16 mm², and typically in a range from 2mm² to 10 mm².

In some embodiments, the RF perforating element consists of asubstantially tubular member made from an electrically conductivematerial including stainless steel, copper, titanium and nickel-titaniumalloys. The tubular element is proximally coupled to the RF generatorand has an electrical insulator disposed thereon to deliver energy to anuninsulated segment or electrode at the distal region with minimaldissipation. The distal end of the tubular element can be open orclosed. The tubular element can be tapered, coupled to a hand-heldactuator, and can be scored to increase flexibility as described herein.In some embodiments, two or more tubular elements can be coupled to formthe RF perforating element.

FIGS. 26A-26F depict the RF ablation device and steps to remove an SDH2610 using such device. FIG. 26A is a schematic illustration of anexample RF stylet 2630 positioned near a wall of the MMA 2620 in adirection toward the subdural hematoma 2610.

Radiofrequency energy is generated by a generator and delivered by one(in a monopolar arrangement) or more (e.g., a plurality) of electrodes(e.g., two electrodes in a bipolar array) attached to the distal end ofthe penetrating member. The electrodes are connected to an electricalwave generator via conductive wires embedded inside or attached to thewall of the penetrating member extending from the distal end to theproximal end of the penetrating member. The conductive wires areelectrically insulated along the whole length except at the very tip.The electrical wave generator generates a high frequency electricalwaveform in a range from 300-600 kHz (e.g., 400 kHz to 600 kHz, 500 kHzto 600 kHz, 300 kHz to 500 kHz, or 300 kHz to 400 kHz) and in a rangefrom 120-220 V (e.g., 140 V to 220 V, 160 V to 220 V, 180 V to 220 V,200 V to 220 V, 120 V to 200 V, 120 V to 180 V, 120 V to 160 V, or 120 Vto 140 V).

In some embodiments, the penetrating member if formed by a stylet 2630with RF capacity and an atraumatic blunt or rounded distal end, as shownin FIG. 26A. In FIG. 26B, the stylet 2630 is shown penetrating throughthe MMA 20 while delivering RF energy 2632 and is followed by coaxialadvancement of a shaft 2620 and then a suction catheter 2600 (FIG. 26B).The stylet 2630 can be used to then advance atraumatically through thesubdural space, or be exchanged by a wire.

In some embodiments, as shown in FIG. 26C, the RF stylet 2630 acquires acurve or a pigtail shape upon emergence from the shaft 2620 or thesuction catheter 2600 (FIG. 26D). This may be beneficial to preventunintentional pullback into the vascular lumen and to prevent brainperforation during device advancement into the subdural space.

In other embodiments, the shaft 2620 has RF capacity. The shaft 2620 isadvanced trans-arterially under fluoroscopic guidance to the perforationpoint, and is then pushed through the arterial wall and dura into thesubdural space while delivering RF energy 2632. Then, a wire can bepushed through the shaft 2620 into the subdural space followed byadvancement of the suction catheter 2600.

FIG. 26D is a schematic illustration showing the distal tip portion ofthe suction catheter 2600 positioned in the subdural hematoma 2610. Fromhere, suction can be applied using the suction catheter 2600 to aspirateblood and/or other fluids to at least partially drain the subduralhematoma 2610, as described above.

FIG. 26E is a schematic illustration showing the suction catheter 2600retracted through the MMA 20 wall and RF energy 2632 applied. In someembodiments, RF energy 2632 is applied to the opening on the MMA 20 wallvia the electrode to induce thermal coagulation (e.g., clotting) toclose the perforation.

FIG. 26F is a schematic illustration showing the MMA 20 including a clot2640 which forms from the applied RF energy 2632 disrupting the walls ofthe MMA 20.

In some embodiments, the penetrating system includes one or moreapertures I the distal segment fluidly coupled to channels to injectcontrast through the injection port to confirm the perforation of thetargeted tissue, saline solution to cool the surrounding tissue toreduce the thermally affected zone during radiofrequency perforation, orsaline solution to increase the lubricity and width of the subduralspace.

In some embodiment, monopolar electrode is used, and another groundingpad is attached to the peripheral of the patient head in a directionalong the vector pointing from the distal end of the penetrating memberto the targeted tissue under the guidance of fluoroscopy. This isbeneficial to enable directional radiofrequency perforation usingminimum energy and creating minimum thermal injury to the surroundingtissues.

In another embodiment, the RF energy 2632 can be applied continuously orin pulses.

In another embodiment, one or more thermocouples are attached near thedistal end of the penetrating member (e.g., near RF stylet 2630) tomonitor the tissue temperature at and/or near the targeted site. Thetemperature signal is transmitted to the electrical wave generator andthe waveform parameters, such as duration and duty cycle of pulsed RFenergy 2632, is modulated via by the electrical wave generator. Forexample, the electrical wave generator includes an algorithm to modulatethe waveform parameters based upon at least the temperature signal fromthe one or more thermocouples, such as proportional-integral-derivative(PID) algorithm and/or Kalman filtering algorithm.

In another embodiment, the penetrating member includes one or more sharpedges, such as a bevel, and perforates the vessels and dura of the MMA20 which reduces the RF energy 2632 to perform the penetration. Inalternative embodiments, the RF stylet 2630 has an atraumaticnon-cutting tip.

In some embodiments, the RF element, which can be the stylet 2630, shaft2620, catheter 2600, or the combinations thereof, includes a combinationof one or more electrode, temperature sensor, and/or pressure sensor. Inone embodiment, two pressure sensors are placed at the distal end of theRF element to sense the contact pressure between the tip of the RFelement and the tissue (e.g., first pressure sensor) and/or the pressureof fluid surrounding the RF element such as the blood or SDH fluid(e.g., second pressure sensor).

The first pressure sensor is placed at the tip of the RF element and thesecond pressure sensor is placed 0.2-2 mm proximal to the first pressuresensor. Such distance is selected to distinguish different stages in theperforation process. When the RF element is navigating to the vascularperforation point, both the first and second pressure sensor measure thenominal blood pressure.

When the RF element is advanced to push against the target tissue withgood wall apposition, the contact pressure is high, reflected by a highreading from the first pressure sensor. Meanwhile, the second pressuresensor is not in contact with the tissue and only measuring the nominalfluid pressure.

During tissue perforation, the contact pressure between the firstpressure sensor and the tissue is reduced from high to nominal while thecontact pressure between the second pressure sensor and the tissue isincreased from nominal to high. After the tissue is perforated, both thefirst and second pressure sensors measure the nominal fluid pressure inthe subdural space. In another embodiment, multiple pressure sensors areplaced in a circumferential manner and the average pressure measurementis used to reduce the bias due to the non-perpendicular contact anglebetween the RF element tip and tissue.

In another embodiment, such pressure measurement thereof is used toactivate and/or terminate the application of RF energy 2632. In atypical perforating procedure, the device is first advanced to thevascular perforation point, and the RF element position and deflectionangle is then adjusted until good wall apposition of the RF elementagainst the tissue is confirmed by the pressure measurement. The RFenergy 2632 is activated, and the RF element starts to perforate thetissue until the tissue is perforated and confirmed by the pressuremeasurement. In another embodiment, such pressure measurement thereof isused to give signals (in a form of light, sound, or other signal) to theoperating clinicians to inform the progress.

In another embodiment, one or more temperature sensors are placed at thedistal end of the RF element to monitor a temperature value during RFactivation and feed the temperature value to the RF generator to providea signal corresponding to a high temperature, or a low temperature. TheRF generator can receive the temperature measurement and regulate the RFenergy 2632 by tuning the device impedance, voltage, duty cycle, pulsewidth, and/or a combination thereof using control functions such asproportional-integral-derivative (PID) algorithm, and/or Kalmanfiltering algorithm, to terminate the RF energy 2632 for safety.

In some embodiments, the shaft 120 can have one or more mechanism tostraighten the tip and one or more mechanism to increase the stiffnessof at least one segment of the shaft 120 (like pulling micro-wiresinside, or a coil pull system).

In some embodiments, at least a segment of the suction catheter 100and/or the shaft is deflectable and/or steerable. Deflection (e.g.,steering) refers to the movement of the distal catheter segment (e.g.,the end) independent of the rest of the catheter. Steerability refers tothe ability to rotate the distal catheter segment (e.g., clockwiseand/or counterclockwise with respect to the rest of the catheter) bytorque transmission along the length of the device.

The torque causing the deflection can be transmitted by one or moreshafts connected to a pull or anchor ring near the device tip. Thedistal catheter segment rotates one or more directions (e.g.,rotational, or flexing within a plane) upon actuation and return to theoriginal shape (e.g., linear). The deflection can be symmetrical,asymmetrical, loop curves, or compound. Deflection can occur in one ormore planes and be on plane and off planes.

FIGS. 27A-27K are schematic illustrations depicting the use of adeflectable catheter. The skull 271, brain 272, dura 274, and the MMA276 are shown with an SDH 2710 between the dura 274 and brain 272.

For example, in some embodiments, the suction catheter 2700 includes oneor more pull wires slidably positioned in a wall of the suction catheter2700. By pulling on the wires, the distal end segment of the suctioncatheter 2700 can be laterally deflected. In some embodiments, thedistal end segment includes the terminal 0.5 cm or more of the catheter2700 (e.g., 1 cm, 1.5 cm, or 2 cm). In addition to using the deflectingcapability to steer the suction catheter 2700, the deflecting capabilitycan also be actuated to anchor (e.g., maintain the position of) thesuction catheter 2700 against an internal wall of a vessel, such as theMMA 276.

Anchoring the suction catheter 2700 against an internal wall of the MMA276 enhances the pushability of the shaft 2720 and/or stylet 2730 anddecreases the kickback (e.g., the likelihood of pushing) the suctioncatheter 2700 out of the MMA 276. While the suction catheter 2700 isanchored against an internal wall of the MMA 276, the ability to pushthe shaft 2720 and/or stylet 2730 within the lumen of the suctioncatheter 2700 is enhanced.

In such embodiments, the suction catheter 2700 can be advanced into theintracranial MMA 276 over the shaft 2720 which was advanced over a wire2705 as shown in FIG. 27A and FIG. 27B. After removing the microwire2705 and embolizing the MMA 276 by injection of embolization agentthough the shaft 2720 (FIG. 27C), the stylet 2730 is advanced to thedistal end of the shaft 2720 (FIG. 27D).

Stylet 2730 advancement can be facilitated by retracting the shaft 2720proximal to the foramen spinosum and then advancing the shaft 2720 andthe stylet 2730 concurrently to the distal MMA 276 lumen. The rotatablesuction catheter 2700 is oriented (e.g., by rotation or deflection) byvisualizing a radio-opaque fluorscopic element with fluoroscopy.

The orientation of the catheter 27 with respect to the dura 274 andsubdural space is determined and the pull microwire is actuatedresulting in deflection of the distal end segment of the suctioncatheter (FIG. 27D). Altering the orientation of the catheter 2700 andanchoring within the MMA 276 lumen maintains the catheter 2700 positionwithin the MMA 276.

The stylet 2730 and shaft 2720 are advanced (concurrently orsubsequently) through the catheter 2700 and penetrate the subduralspace, as shown in FIG. 27E, and advance into the subdural space, asshown in FIG. 27F. The stylet 2730 can be exchanged for a microwire 2705with an atraumatic tip and, in some embodiments, can include a shape,such as a J shape as described above. The stylet 2730 advances into thesubdural space and into the subdural hematoma 2710 (FIG. 27G).

The shaft 2720 advances over the microwire 2705. The wire 2705 can beless stiff (e.g., flexible) in distal regions and more stiff in proximalregions to provide stability and support to the advancement of the shaft2720 and suction catheter 2700. Then, the suction catheter 2700 isadvanced through the arterial wall over the shaft 2720 and microwire2705 (or stylet 2730 if not exchanged) into the subdural space andadvanced into the SDH 2710 (FIG. 27H). The microwire 2705 is thenremoved (FIG. 27I) and the SDH 2710 evacuated by aspiration (FIG. 27J).The arteriotomy is closed using a hemostatic element, such as ahemostatic coil 278 (FIG. 27K).

In some embodiment, the shaft 2720 has cutting features at the distaltip which includes a bevel, and a lumen to dispose a wire 2705. In thisembodiment, the shaft 2720 is advanced distal to the catheter 2700distal end and pushed to penetrate the dura 274, followed by coaxialadvancement of the microwire through the subdural space. In someembodiments, the suction catheter slides over the shaft 2720 to navigateinto the subdural space. In other embodiments, the shaft 2720 isadvanced over the microwire though the subdural space followed bycoaxial advancement of the suction catheter.

FIGS. 28A through 28C are schematic illustrations depicting a suctioncatheter 2800 including two actuators 2850 (e.g., a pull wire attachedto an anchor), including actuator 2850 a and actuator 2850 b,respectively. The pull wires of FIGS. 28A through 28C are shown asdashed lines and the anchors as dark bands transverse the catheter 2800axis. The catheter 2800 is shown advanced into the MMA 286 lumenadjacent the dura 284. In some embodiments, the actuators 2850 are pullwires attached to a ring anchor arranged circumferentially around theinner lumen the catheter 2800. In some embodiments, the actuators 2850are anchored circumferentially to the outer surface of the catheter2800. Including two actuators 2850 at two positions within the catheter2800 provides a means to create a torque between the two actuators 2850and create higher angle deflections than using a singular actuator 2850.

FIG. 28A is a schematic illustration of a catheter 2800 within the lumenof an MMA 286 adjacent the dura 284. In some embodiments, a firstactuator, e.g., actuator 2850 a, is anchored more proximally (e.g.,further from the distal end of) along the catheter 2800 than a secondactuator, e.g., actuator 2850 b, which is anchored more distally thanthe first. The pull wire connecting the first actuator 2850 a isslidably disposed along a surface of the catheter 2800 along a firstroute and the second actuator 2850 b pull wire is slidably disposedalong the surface along a second route. The first actuator 2850 a isactuated which deflects the suction catheter 2800 in the MMA 286laterally at the location of the ring anchor of actuator 2850 a, whichin FIG. 28B is next to the foramen spinosum. As shown in FIG. 28C, thesecond actuator 2850 b pull wire is actuated to deflect the suctioncatheter 2800 tip medially towards the dura 284, for example, in asecond, different direction than the first actuator 2850 a wasdeflected.

FIGS. 29A and 29B are schematic illustrations of depicting a singleactuator 2950 (e.g., a pull wire attached to an anchor) deflecting thecatheter 2900 distal tip. The pull wire of FIGS. 29A and 29B is shown asa dashed line and the anchor as a dark band transverse the catheter 2900axis. In some embodiments, one or more actuators 2950 can be attached tothe catheter 2900 following a pathway, e.g., a linear, curved, “s”shaped, or spiral pathway, along the suction catheter 2900 wall leadingto one or more articulation points and/or deflections in one or moredirections. This configuration can actively assist in spatiallyarranging the suction catheter 2900 in an advantageous manner.

For example, the actuator 2950 articulates the suction catheter 2900 toform a curve with a concavity centered at the foramen spinosum (entrypoint of the MMA 296 to the intracranial compartment). The actuator 2950articulates the suction catheter 2900 medially and directs the catheter2900 outlet towards the dura 294 and the subdural space. For example, aspirally-aligned actuator 2950 capable of articulating the suctioncatheter 2900 to curve the distal segment both medially and laterallywill accommodate catheter 2900 insertion and traversing the MMA 296 fordirectable penetration into the subdural space by following the anatomyand fixation points at the skull base and dura 294.

In some embodiment, articulation of the suction catheter 2900 can beachieved with one or more actuators which can provide actuators 2950 or2850, such as pull wires, notches, preset curves, shapes, and/or anyother mechanism obvious by the ones skilled in the art. In someembodiments, the actuators, such as the pull wires or other articulatingelements, are present in the shaft.

In some embodiments, one or more passive (e.g., non-articulable) wirescan be used to stabilize and provide direction to the suction catheter2900.

In some embodiments, insufflating a balloon, deploying a stent, or otherexpandable element disposed in a distal vascular segment andmechanically connected to one or more of the telescoping elements canenhanced pushability of the perforating element and decrease kickback.

In some embodiments, enhanced pushability of the shaft 120 and/or stylet130, decrease the kickback of the suction catheter 100 anddirectionality can be achieved by advancing over a wire a deliverysheath with a branching annex into an arterial bifurcation. FIGS. 30Athrough 30E are schematically illustrations depicting a suction catheter3000 including a second catheter 3002 affixed to the exterior surface atan arterial bifurcation, such as a bifurcation in the MMA 306. Thesecond catheter 3002 has a smaller inner lumen then the first catheter3000.

The MMA 306 typically is located in the epidural side of the dura andthat typically has a bifurcation in a plane parallel to the dura. Acatheter 3000 including a second catheter 3002 can include an annex tohold the MMA 306 bifurcation and stabilize the catheter 3000 positionprovides 3-dimensional orientation to perforate the MMA 306 wall anddura in a perpendicular medialized trajectory.

FIG. 30B depicts the annex 3010 as a wire having a J-shaped distal end,though the annex 3010 can be a hypotube, catheter, stent, balloon, orother deployable element sufficient to provide an arresting tension tothe catheter 3000 and second catheter 3002. In embodiments in which theannex 3010 is a wire, it can travel in the main catheter 3000 lumen orin the second catheter 3002 lumen arranged or affixed to the maincatheter 3000 wall. The annex 3010 is disposed as an independentcomponent or as a deployable appendage from the delivery catheter 3002.

The catheter 3000 has a pre-made orifice 3004 that provides off-axisopening orientable towards the subdural space allowing access to theperforating element 3012. In some embodiments, the perforating element3012 is a needle that is advanced though the catheter 3000 to penetrateinto the subdural space (FIG. 30C). The shape of the perforating element3012 can be permanent or composed of a malleable material (e.g.,nitinol).

The shape can be also provided by a shaped inner element within theperforating element 3012. The distance that the perforating element 3012is advanced beyond the suction catheter 3000 or delivery sheath iscalled the perforation distance (dp). This distance, dp, can be fixed,temporarily fixed, or adjustable by the handle as described herein.

In some embodiments, the perforating element 3012 is hollow and acontrast agent can be injected into the subdural space though theperforating element 3012 lumen. FIG. 30C depicts a perforating element3012 injecting a contrast agent 3015 into the subdural space. Theperforating element 3012 tip position can then be visualized incomparison to the contrast agent to ensure an intradural needle tiplocation. Alternatively, other fluids can be injected through theperforating element 3012 lumen. For example, injection of fluid, such aswater, to increase the size and lubricity of the subdural space.

FIG. 30D depicts a microwire 3014 advanced co-axially through theperforating element 3012 into the subdural space, for example, into anSDH. In some embodiments, a third suction catheter 3016 can be advancedover the perforating element 3012 though the dura and over the microwire3014, such as to the subdural location of the SDH, as shown in FIG. 30E.The risk of losing access to the subdural space after creation of thetransarterial passageway decreases by advancing a wire into the subduralspace.

In some embodiments, the suction catheter distal end segment includes abeveled tip, e.g., the opening to the suction catheter includes anovalized opening and the tip plane can be at an angle with respect tothe transverse plane of the suction catheter. In some embodiments, thebeveled tip includes a fluorscopic element for orientation.

The suction catheter beveled tip facilitates MMA wall penetration intothe subdural space. The suction catheter penetration capabilities areincreased when combined with a cutting edge. The beveled tip improvesapposition between catheter lumen and penetrating surface. The beveledtip provides improved penetration directionality and facilitatesevacuation of an SDH.

As an example, a suction catheter is positioned within the MMA androtated under fluoroscopic observation (e.g., fluoroscopy) until thebeveled tip faces the MMA wall. Penetration is accomplished by any ofthe embodiments disclosed herein, including but not limited to advancinga stylet and/or a shaft into the subdural space and penetration with thesuction catheter, or, alternatively, penetration with a pre-shapedcurved needle followed by wire advancement in the subdural space.

In some embodiments, the suction catheter has an actuator (e.g., a pullwire) to position the beveled tip against the arterial wall and orientthe tip towards the subdural space which facilitates directionalpenetration while providing more column strength to minimize kickback.In some embodiments, the depth of penetration of the shaft and styletcan be maintained and adjusted with a handle. A typical depth ofpenetration includes a range from 1 mm to 10 mm (e.g., from 2 mm to 10mm, 4 mm to 10 mm, 60 mm to 10 mm, 8 mm to 10 mm, from 1 mm to 8 mm,from 1 mm to 6 mm, from 1 mm to 4 mm, or from 1 mm to 2 mm).

The depth of penetration is adjustable based on, in some examples,images obtained before or during the intervention, such as CT scan imageand/or brain MRI image. The stylet and/or shaft advances into thesubdural space into a final position and the handle operated to lock theshaft position. The stylet is removed and contrast injected into thesubdural space. The area is imaged using a method described herein toconfirm the subdural location of the shaft distal end. A wire isadvanced coaxially into the shaft into the subdural space.

In some embodiments, the perforation can be created with a curved (e.g.,“S” shaped) perforation element (e.g., a needle) that first mediallypenetrates the MMA wall and dura and curves laterally away from (e.g.,along the surface of) the brain to direct the bevel facing the subduralsurface of the dura. The curvature of the perforation element distalsegment results in a proximal segment parallel to the MMA lumen, anintermediate segment transitioning at an oblique angle though the MMAwall and dura, and a distal segment within the subdural space that isparallel to the dura and the brain. This embodiment reduces the risk ofunwanted brain perforation and, in the case of brain perforation,ensures that wire advancement will follow a trajectory to re-enter thesubdural space.

In some embodiments, the actuator articulates the suction catheter todeflect towards the apex of the bevel followed by perforation with anyof the elements previously described including needle and shaft.

In some embodiments, the perforation element can be the stylet or asuction catheter. In some embodiments, in cases when the perforation isdirected into the SDH, the needle can be connected to a vacuum source todrain the SDH, or the perforation element can be retracted resulting ina passageway between the SDH and the catheter lumen. In someembodiments, the telescoping elements (e.g., the suction catheter, thestylet, the sheath, and/or the microcatheter) includes one or morestructural elements (e.g., rails) to increase the element stiffness,minimize unwanted rotation, and maintain the orientation along theplane.

In some embodiments, the device includes an imaging component, such as atomography component. For example, the device can include an opticalcoherence tomography (OCT) or an intravascular ultrasound (IVUS)tomography component. In embodiments using IVUS, the followingechogenicity appearances for biological components provide orientation.The dura and dural appendages are hyperechoic. The cerebrospinal fluidis hypoechoic. The brain superficial pia mater is a well-definedhyperechoic layer overlying the hypoechoic cortical gray matter, whichoverlies the hyperechoic white matter. The subarachnoid space containsnumerous vessels on Doppler mode of the ultrasound. The subduralcollection includes rare or no vessels on Doppler, can have hyperechoicmembranes, and can be hyperechoic, hypoechoic, or a combination.

FIGS. 31A through 31D are schematic illustrations of a device includingan image component arranged within an MMA 316. FIG. 31A depicts adelivery sheath 3100 anchored by a microwire 3110 and a secondary annexmicrowire 3111 within the MMA 316. The perforation element 3112 is shownpenetrating the MMA 316 wall and the can optionally include a deliverysheath with one or more lumens that is advanced over microwire 3110 intothe distal MMA.

The delivery sheath 3100 be rotated to direct an opening in the distalend to the penetration point. Typically, the delivery sheath 3100 hashigher inner and outer diameter proximally and tapers (e.g., lower innerand outer diameter) distally. This increases delivery sheath 3100flexibility aiding in entering the foramen spinosum and the intracranialMMA 316.

The opening can be at the distal end of the delivery sheath 3100 or inthe lateral wall (e.g., such as opening 3004) proximal (e.g., within 5cm of) to the distal end. Leveraging the bifurcation of the MMA 316 inthe outer surface of the dura, the delivery sheath 3100 advances in thedominant branch (e.g., the right branch of FIGS. 31A) and the annexmicrowire 3111 is advanced into the second branch of the MMA 316bifurcation (e.g., the left branch of FIG. 31A). This orients thedelivery sheath 3100 in space and disposes an opening towards theperforation point perpendicular the plane of the bifurcation andmedially (e.g., towards the brain).

The orientation of the delivery sheath 3100 can be guided by rotatingthe device to follow radiopaque markers and/or fluoroscopy.Alternatively, the imaging component 3160 (e.g., the OCT or IVUScomponent) can be used to image the MMA 316 branch lumen and rotatingthe device to orient the delivery sheath 3100 and microwire 3110 withcorresponding angular markers, such as detected biological markerswithin the MMA 316.

One or more penetrating elements (perforating element 3112, stylet,shaft, or suction catheter) are advanced towards the opening and the MMA316 wall and dura perforated. The perforating element 3112 can be madeof a memory material (e.g., nitinol) which curves upon aperture egress,or the aperture can be coupled to an angled surface to provide an angleof attack to the dura greater than 1 degree (e.g., greater than 2degrees, greater than 5 degrees, or greater than 10 degrees). Theperforating element 3112 can be pre-shaped from a memory material (e.g.nitinol) and advanced to penetrate into the subdural space and enableco-axial advancement of a microwire to the SDH.

A suction catheter can be advanced over the perforating element 3112though the dura and then over the wire though the subdural space to thelocation of the SDH. The perforating element 3112 can be alternativelybe exchanged for a suction catheter which will be advanced over a wirefrom the intravascular space to the SDH. In some embodiments, the deviceperforates the dura on top of the SDH. In these cases, after advancementof the perforating element 3112 and piercing of MMA 316 wall and dura,the perforating element 3112 will enable drainage of SDH.

In some embodiments, the perforating element 3112 is reinforced by astylet for penetration though the dura. After penetration, the styletcan be removed providing a lumen to the perforating element 3112 todrain the SDH. In some embodiments, after penetration with theperforating element 3112 into the SDH, a length of exchange wire can beadvanced (into the subdural space though the perforating element 3112and the device can be removed and exchanged over the wire for a suctioncatheter. The exchange wire length is in a range from 250 cm to 300 cm.The suction catheter advances over the wire though the arteriotomy siteinto the subdural space and accesses the SHD. The wire is removed andthe SDH drained.

Referring now to FIG. 31D, an embodiment which maximizes the size of thesuction catheter is shown. The suction catheter is delivered though thelumen of the delivery sheath 3100. The delivery sheath 3100 advancesinto the MMA 316 bifurcation and is oriented by use of a wire in eachbranch of the MMA 316.

The delivery sheath 3100 has an opening in the distal end which enablesthe advancement of a perforating element towards the MMA 316 wall anddura. In some embodiments, the direction of the perforating element canbe provided by using a pre-shaped perforating element 3112 with a curvedorientation and is oriented with fluoroscopy to perforate the MMA 316wall medially and perpendicularly.

Orientation can be also provided by a rail system connected to the inneror outer surface of the delivery sheath 3100 and/or the perforatingelement 3112. In alternative embodiments, the perforating element 3112advances towards a deflecting surface fixed in the ID of the deliverysheath 3100 resulting in advancing of the perforating element 3112towards the opening and perforating point.

In some embodiments, the perforating elements herein described is usedto perforate through membranes and septations associated with mixed-agedSDH and chronic SDH.

In some embodiments, the perforating element 3112 is fluidly connectedwith one or more apertures at or near the distal end which allowsinjecting of fluid, including a contrast agent, or saline.

In some embodiments, the perforation process and ingress in the subduralspace monitored by including one or more sensors in the device,including pressure sensors, e.g., potentiometric pressure sensors,inductive pressure sensors, capacitive pressure sensors, strain gaugepressure sensors, fiber optic pressure sensor, variable reluctancepressure sensors, microelectromechanical system pressure, andpiezoelectric pressure sensors.

A piezoelectric pressure sensor includes piezoelectric film disposed inthe OD of the perforating element 3112 in proximity to the distal end tocapture a pressure signal, the signal including a pressure peakassociated with penetration through the MMA 316 wall and by pressuredrop upon accessing the subdural space. Pressure sensors can also sensethe pressure waveform (e.g., arterial, intracranial, or venousperforation waveforms) upon penetration from the vascular lumen into theintracranial compartment.

In some embodiments, the perforation process and ingress in the subduralspace is monitored by measuring spectroscopy values of tissues.

In some embodiments, the perforation process and ingress in the subduralspace is monitored by measuring an impedance value and/or a permittivityvalue of tissue and fluids. FIG. 39 is a line chart comparing thepermittivity value on the y-axis to the frequency in kHz of theelectrical signal (e.g., the RF energy) on the x-axis. FIG. 39 includesfour example tissues (e.g., blood vessel wall, dura, or brain surface)or fluid (e.g., blood) represented by lines of FIG. 39 . The individuallines represent the permittivity of the example tissue or fluid withrespect to the applied energy frequency, according to the key inset inthe upper right. Blood (solid line) has the highest permittivity acrossthe depicted frequencies, with a brain surface (dotted line) havinglower permittivity than blood, the blood vessel wall (dashed line)having lower permittivity than the brain surface, and the dura(dash-dotted line) having the lowest permittivity up to approximately720 kHz and the blood vessel wall having the lowest permittivity aboveapproximately 720 kHz.

Permittivity is an intensive (e.g. independent from the volume or massof object or tissue) electrical property of tissue. Tissue with higherpermittivity has lower impedance when transmitting alternating current,or in the invention described here, RF current. Blood has higherpermittivity compared to the brain surface, followed by the blood vesselwall and dura in the RF frequency range (e.g., in a range from 100 to1000 kHz).

In a typical operating RF energy frequency range (e.g., 300-600 kHz),the permittivity of blood is 4 times higher than that of the brainsurface and over 10 times higher than that of the dura and blood vesselwall. Such large difference in permittivity can be used to detect thelocation of the RF element. During RF penetration, the RF element issensing a low permittivity (or high impedance) from the dura and thevessel wall. Once the dura and vessel wall is perforated, an increase inpermittivity (or decrease in impedance) is measured as the RF elementgoes into the subdural space and contacts the brain or SDH. Suchimpedance signal is fed to the RF generator to automatically reduce orshutoff the RF power and/or notify the operating clinicians in a mannerof sound, light, vibration or a combination thereof. After completingthe intradural intervention, the apparatus including the RF element ispulled back into the vascular lumen and again surrounded by blood. Thisresults in an increase of permittivity (or decrease in impedance). Suchpermittivity and/or impedance signal is fed to the RF generator tomodify (e.g., raise, lower, initiate, or terminate) the RF power to acoagulation mode, and/or provide a notification to the operatingclinicians in a manner of sound or light or a combination thereof.

In some embodiments, the perforation process and ingress in the subduralspace is monitored by including a force sensor at the proximal end ofthe perforating element to measure a thrust force associated withpenetration through the MMA 316 wall.

In some embodiments, the perforation process is followed by measuringpressures at the tip of the perforating element by channel fluidlycoupled to a pressure transducer which can be outside the patient.

In some embodiments, the perforation process is followed by recordingelectroencephalographic (EEG) activity with an electrode (e.g., EEGmeasuring device) disposed at or within 20 mm from the front end of thepenetrating element and electrically coupled to an EEG recorder whichcan be outside (e.g., external to) the patient. In some embodiments, theEEG measuring device can function as the RF energy delivery device, suchas RF stylet 2630. In this embodiment, an EEG interface device operatingas a splitter enables concurrent connection of the device to an RFgenerator and an EEG recorder. This embodiment facilitates continuousEEG recording concurrently with RF energy 2632 delivery.

The construction of the stylet, shaft or catheter to achieve thesefeatures comprises one longitudinal element selected from the groupconsisting of a hypotube, single solid rod, multiple roads, bundle,tubing (with one or more lumens), shaft strands, cable (two or morewires running side by side, bonded, twisted or braided), coil, braid orcombinations thereof.

In some embodiments, the device subcomponents can be made of metal ormetal alloy (including but not limited to stainless steel, nitinol,silver, titanium, copper, cobalt chromium, nickel chromium, platinumiridium, and others), polymer (including but not limited to nylon orother polyamides, fluoropolymers, polyolefins, polythetrafluoroethylene,high density polyethyene, polyurethanes and polyimides), ceramic,bio-absorbable or dissolvable components, or combinations.

The construction of the device can include inner liners and outerjackets and the manufacturing techniques are known by those skilled inthe art. These elements may be necessary to enhance the structuralsupport to the device, facilitate smooth telescoping between components,prevent vacuum leaks by sealing holes, and enhancing the flow ofhematoma to be drained and reduce the likelihood of clots and fibrin toclog the suction catheter.

It is beneficial for the elements of the device herein to remain highlyflexible to navigate into the intracranial compartment and havesufficient column strength to perforate and advance into the subduralspace. In some embodiments, the elements of the device have a tipbending stiffness in a range from 0.0002 lbf·in2 to 0.005 lbf·in2 with atypical value around 0.001 lbf·in2 for navigating to/within the MMA. Insome embodiments, the elements of the device have a bending stiffness of0.006 lbf·in2 to 0.15 lbf·in2 with a typical value of 0.028 lbf·in2 fornavigating to/within the SSS. To this end, the elements have sections ofvarying stiffness. This is accomplished by employing and combiningdifferent element construction configurations, materials, ration ofmaterials, thicknesses, amount of material, materials with differentdurometer, and/or selective reinforcement.

In some embodiments, any of the subcomponents may include a plurality ofscorings to increase element flexibility, for example, to transverse thecurves of foramen spinosum. The plurality of scorings can take a shapeor pattern including but not limited to spiral scoring patterns(continuous or interrupted), radial scoring patterns, bespoke scoringpatterns, radial ring patterns, longitudinal scoring, oblique scorings,windows, tabs, or holes. Scorings may be created in the elements byusing any suitable scoring methods including laser scoring and etching.Scorings can be in at least a portion (e.g., a segment) of thesubcomponent and in some embodiments are preferentially located on oneside.

In some embodiments, any of the subcomponents have one of the followingprofiles along its length: continuous, tapered in distal direction,tapered in proximal direction, multi tapered and combinations thereof.

Generally, subcomponents are larger, stiffer, and have higher torquetransmission proximally and will taper distally and have increasingflexibility to enter the foramen spinosum and intracranial MMA.

In some embodiments, any subcomponent, including stylet, shaft orcatheter is constructed with two or more layers of high-tensile wirewound at opposing pitch angles resulting in flexible elements with hightorsional stiffness.

In another embodiment, the subcomponents, including stylet, shaft,catheter, anchoring element, or protective sheath, can have a railingsystem along at least a portion of the length with one of the followingcross-sectional shapes: circular, oval, square, start, diamond,rectangular, flat, or a combination thereof. The receiving lumenconforms to the shape of the inner member. The receiving lumen IDapproximately matches (e.g., within 0.002″) the OD of the inner memberto restrict non-longitudinal motion or is shaped to allow a limitedpreset range of rotational motion. In some embodiments, thesubcomponents include one or more rail systems per subcomponent, and therail system can include the full subcomponent length.

Non-circular configurations of the stylet and shaft can limit therelative rotation between subcomponents while maintaining the capacityto telescope along the longitudinal axis (e.g., longitudinally). Suchnon-circular embodiments help to maintain the trajectory of theperforating element over the guide element towards the perforationtarget. As one example, the rail system may be beneficial when advancingthe penetrating element over a distal anchoring element. In thisexample, the anchoring element (balloon or stent or other) can beconnected to the device by a flat wire. The flat wire can allow elementadvancement over the wire of the perforating element (or protectivesheath) to the perforation point. In other embodiments, radial alignmentbetween telescoping elements can be maintained by coupling longitudinalrecesses and fins at the interfacing surfaces.

In some embodiments, deploying a stent or insufflating a balloondisposed in a distal segment of the shaft 120 in the extravascular spacecan provide improved purchase to push a suction catheter 100 into theextravascular space.

Fluoroscopic elements that are highly visible under fluoroscopy can belocated on any of the components in any locations as desired.

In some embodiments, the fluoroscopic elements construction can includeelements indicating the direction of the deflecting element. Thedirection of the deflecting element indicates the plane to which themarker will direct the subcomponent, e.g., the plane of deflection. Forexample, the marker can be a partial circle with a notch matching theplane of deflection, or the plane of deflection can be marked by thepartial radiopaque circle, or by an asymmetry in the marker. Alternativeexamples of fluoroscopic elements include an arrowhead, ring, or bandsymbol or structure.

In some embodiments, the fluoroscopic elements provide support to theperforating element in a circumferential fashion.

In some embodiments, the fluoroscopic elements decrease the cuttingforce required to perforate the MMA and/or dura, such as a fluoroscopicmarker including a beveled tip, or cutting tip.

In some embodiments, the fluoroscopic elements can be tapered todecrease the gap with the OD of a telescoping element.

In some embodiments, two or more fluoroscopic elements are present in asubcomponent. For example, the shaft or the catheter can have onefluoroscopic elements distally to indicate the distal end of the device,and another fluoroscopic elements in a more proximal segment to indicatethe detachment of the element to close the arteriotomy, includingoff-the-shelf coils.

In some embodiments, two or more different subcomponents have two ormore fluorscopic elements which indicate longitudinal and or rotationalalignment between subcomponents. These fluorscopic elements can includesymbols (e.g., “bullseye”), forming intersecting shapes (e.g., “T”, “L”,“+”, or “X”), or other way evident by those skilled in the art.

In some embodiments, the distal end portion of the shaft 120 or styletcan have elements (e.g., ridges, fins, wedges) or shapes to maintain thetip of the shaft 120 away from the brain surface. The shape can bepermanent, temporary, or reversible. For example, compacting areversible shaped element composed of a memory material (e.g., nitinol)within a subcomponent and, after emerging from the subcomponent, theelement resumes the original shape; alternatively, the shape is resumedafter removing a rectifying (e.g., constraining) element.

In some embodiments, the shaft 120 or stylet (or other subcomponent)includes a shaped inner element and the shape of the distal end portionof the shaft 120 or stylet (or other subcomponent) corresponds to theshape of the inner element. The inner element can be a rigid orsemi-rigid element within a portion of the length of the subcomponentand be composed of a rigid, or semi-rigid material, such as a memorymaterial.

For example, the inner element and corresponding subcomponent shape caninclude “S” shapes wherein the distal end portion is directed towardsthe dura for penetration and a proximal end portion is outside the dura,with a connecting portion angled with respect to the distal and proximalportions. After a distance of advancement (e.g., the length of theconnecting portion) wherein the distal end of the outer coaxial elementextends through the dura, for example extends through the dura bybetween 1 mm and 5 mm, the shape is formed directing the tip away fromthe brain. In some embodiments, the distance of advancement is in arange from 0.1 mm to 15 mm (e.g., from 1 mm to 15 mm, from 5 mm to 15mm, from 10 mm to 15 mm, from 0.1 mm to 10 mm, from 0.1 mm to 5 mm, orfrom 0.1 mm to 1 mm). A second curve proximal to the distal most “S”shape can help orienting the curves of the shape parallel to the brainand dura surface.

In some embodiments, one or more subcomponents include one or moreanchoring features to anchor the subcomponents to the subdural surfaceof the dura after penetration, or to anchor to an intradural surface.Examples of these anchoring features include wires (including shapedwires, e.g., pigtail wires), stents, balloons, arrowheads, wings, fins,loop, bend, harpoons, spikes, hooks, and/or barbs. These anchoringfeatures anchor a subcomponent of the device (such as the stylet, orshaft) after penetration and enable more tensional load to be applied tothe outer penetrating elements during advancement through the MMA walland dura. These anchoring features may be compressible (e.g., formed ofa low durometer material) to be recaptured.

In some embodiments, the anchoring features are actuatable to anchor thesubcomponent upon actuation or activation. Alternatively, the anchoringfeatures are fixed (e.g., static) to provide anchoring coincident uponingress into the extravascular compartment. In some embodiments, thepenetrating element can become the anchor upon actuation or advancement.As an example, the stylet can be used to penetrate through the vascularwall and dura, and upon emergence from an enclosing subcomponentacquires a pigtail shape which coincidently anchors the stylet in thesubdural space. The stylet pigtail shape provides an atraumatic tip uponadvancement in the subdural space.

In some embodiments, one or more subcomponents have one or morearresting features which minimize the risk of unintentional subcomponentretreat into the artery after perforation of the arterial wall or dura.This is advantageous as retreat may result in bleeding though thearteriotomy. The arresting features include elements that expand and/ordeploy resulting in a larger dimeter than the subcomponent carryingthese elements (or alternatively expand the subcomponent diameter), andexamples of arresting features include barbs, fins, wires, collar, rib,rim, ribbon, and baskets. In some embodiments, the arresting featuresare recaptured (e.g., retracted). Other limiting feature examples can beelements that reduce the subcomponent diameter along a portion of thesubcomponent length such reversible bevels, indentations, or notches. Insome embodiments, the arresting features are manually or automaticallyretractable (e.g., hidable).

In some embodiments, one or more subcomponents include one or morelimiting features to limit the longitudinal advancement. For example,the limiting features limit subcomponent penetration depth to within adistance of the dura perforation. The limiting features include elementsthat expand and/or deploy resulting in a larger dimeter than thesubcomponent carrying these elements (or alternatively expand thesubcomponent diameter), and examples of arresting features includebarbs, fins, wires, collar, rib, rim, ribbon, and baskets. In someembodiments, the limiting features are recaptured (e.g., retracted).Other limiting feature examples can be elements that reduce thesubcomponent diameter along a portion of the subcomponent length suchreversible bevels, indentations, or notches. In some embodiments, thelimiting features are manually or automatically retractable (e.g.,hidable).

In some embodiment, the perforating element can have fixed features tolimit the penetration depth. This is beneficial when the perforatingelement is not intended to advance beyond a point but enable an innerelement and or an outer element to be advanced distally. As an example,a beveled shaft can be the penetrating element that pierces the arterialwall and dura until and advances into the subdural space and is stoppedby a rim. At this point, a microwire is advanced inside the shaft anddistally into the subdural space. Then, the suction catheter is advancedover the shaft though the vessel wall and over the microwire though thesubdural hematoma while the fixed shaft is providing column support tothe remaining advancing elements.

In some embodiments, the perforating element that initially pierces thedura has features that deploy in the unconstrained subdural space toprevent brain perforation.

In some embodiments, one or more device subcomponents could have one ormore features to minimize the risk of unintentional pull back into theartery after perforation and to limit the longitudinal advancementbeyond a certain point.

In some embodiments, the suction catheter can be telescoped through thesubdural space beyond the distal end of the stylet or shaft. In one ofthese embodiments, the stylet with a beveled tip can be advanced topenetrate the arterial wall and the dura. The shaft can be advanced overthe stylet to penetrate the arterial wall and dura. The stylet can beremoved, contrast injected though the shaft to ensure a subdurallocation of the tip and to map the intradural target, and an atraumaticmicrowire advanced coaxially into the shaft and then distally into thesubdural space. The shaft can be advanced over the microwire into thesubdural space followed by subsequent coaxial advanced of the catheter.After reaching the target with the distal tip of the suction catheter,the inner elements are pulled out.

In other embodiments, the shaft is constructed to provide proximalsupport and only perforate the arterial wall and dura over the styletfor short distances (e.g., 1 mm to 20 mm) to facilitate the perforationof the outer catheter, which will then be advanced into the subduralspace over the microwire.

In other embodiments, a protective sheath can be added to thetelescoping system and be disposed over the perforating subcomponent.The protective sheath can be disposed throughout the length of theperforating subcomponent or be selectively disposed to cover the distalsegment of the perforating component. In such cases, the protectivesheath is translated longitudinally by one or more pull or push wires.The protective sheath protects the cutting features of the perforatingelement and the inner surface of the delivery catheter during theadvancement of the perforating element to the target. The protectivesheath provides orientation for the inner perforating element when theprotective sheath is coupled to the anchoring element (balloon, stent,etc.) by a rail system as described herein. The protective sheathenables a perforation element to acquire a memory shape when unsheathedfrom the protective sheath. The protective sheath can have one or morefluorscopic elements to indicate the location of the perforatingelement.

In other embodiments, the shaft is constructed with perforating elementsdescribed elsewhere herein and actuated to perforate the arterial walland dura without an inner stylet. The shaft can have a lumen to inject aradio-opaque contrast agent to ensure that the tip opens to the subduralspace. The shaft lumen could also be used to infuse saline which wouldflow with low resistance if injected in the subdural space, and at ahigher resistance if injected into the brain parenchyma. An atraumaticstylet or microwire can be coaxially introduced inside and beyond to theshaft into the subdural space. The suction catheter can be advanced overthe shaft though the arterial wall and the dura, and then over thestylet/microwire inside the subdural space.

Any of the elements herein described can be telescoped co-axially and/orover the wire rapid exchange system.

In some embodiments, any of the elements or subcomponents hereindescribed can have reinforcements to increase the column strength ofthat particular element.

In some embodiments, the distal end of the stylet, shaft, and/orcatheter includes a commercially available hypodermic needle or vascularaccess needles. The length of the needle tip reduces the applied forceto penetrate the arterial wall and dura and increases the ease ofnavigation through the curvature at the foramen spinosum. Longer bevelsresult in lower puncture forces but higher likelihood of not trackinginto the intracranial MMA. Bevels with a length less than 1.5 mmobtained from commercially available 28 G needles welded at the distalend of a stylet (e.g., rope-like element with diameter 0.015″) can beadvanced within a shaft having an ID of 0.016″ and an OD of 0.024″through the foramen spinosum inside a catheter having an ID 0.030″ andan OD of 0.043″ located in the MMA. The needle can include plurality ofcuts to increase flexibility while maintaining column strength asdescribed elsewhere.

Generally, arterial navigation is facilitated by maintaining the tip ofthe needle at the front end of the stylet 1 mm distal to the shaft,flush with the shaft, or within 10 mm of the distal end of the shaft.Needles can be larger, the same size, or smaller than the element theyare welded on. Minimal gaps (e.g., a diameter difference of less than0.2 mm) between the telescoping elements reduce the likelihood ofcatching at the artery/dural wall.

In some embodiments, the distal part of the shaft 120 includes aballoon. The shaft 120 can be centered or off-centered position and havea parallel or diagonal emergence from the suction catheter 100. Theinflation of the balloon can be used to: (i) provide support to theshaft 120 for advancement through the arterial wall and/or in thesubdural space, (ii) occlude the arteriotomy of the parent artery toprevent blood extravasation, (iii) enlarge the arteriotomy to facilitatepassage of the suction catheter 100 pushed the brain surfaceinsufflated, (iv) provide distal support/anchorage to facilitate overthe shaft advancement of the suction catheter 100 into the subduralspace, (v) push the brain surface away from the shaft 120 duringadvancement, and (vi) unclog the catheter 100 of particulate matter.

In some embodiments, the distal part of the shaft 120 includes a balloonto create an extradural, intradural of subdural corridor for suctioncatheter 100 advancement.

In some embodiments, the shelf between the catheter 100 and the shaft120 can be tapered. In another embodiment, the catheter 100 can have oneor more bevels to direct advancing forces away from the brain surfaceand towards the SDH. Such a taper design can facilitate advancementthrough the arterial wall, the subdural space and into the SDH.

In some embodiments, the shaft 120 has a larger diameter tip as a “cap.”The diameter of the cap can be smaller or equal to the outer diameter ofthe catheter 100. The cap can be round or conical with the apex of thecone centered or off centered. The interface between the cap and thecatheter 100 can be perpendicular to the main axis, oblique, or acombination. For penetration and advancement modes, the cap can bedisposed in proximity or touching the distal end of the catheter 100 bya pull wire to enhance the pushability of the system and conceal thecatheter edges (which may facilitate advancement through the arterialwall and the subdural space into the SDH). For aspiration mode, the capcan be separated from the tip end of the catheter 100 by a push wire toopen an entry point and aspirate. If the tip of the catheter 100 clogs,the cap be withdrawn by pull wire to unplug the catheter 100.

In some embodiments, the tip end of the catheter 100 can be closedand/or have different shapes. The catheter 100 can have sideholes/fenestrations to aspirate fluid. In some embodiments, the catheterend is tapering and has no opening at the tip. This design has no ledgeand therefore is highly atraumatic. Some embodiments may have an openingat the end to allow coaxial advancement of a shaft disposed at leastpartially inside the catheter 100.

In some embodiments, the distal tip of the catheter 100 can have beveland sharp edges to facilitate the entry into the subdural space andelement in the wall to prevent penetration into the brain. Catheters 100with an oval lumen rather than round can decrease likelihood of brainpenetration. Catheters with beveled tip can facilitate drainage of fluidand clots.

In some embodiments, catheters can have a distal funnel to enhancedrainage of fluid and clots. The funnel can be open by a balloon system,pull or push wires, or have a braided design or slotted hypotube designthat can be introduced in a compressed state and then expand into afunnel after unsheathing.

The lumen of the catheter 100 can be configured to enable irrigation ofsolutions, drugs, cells, or particles. In some embodiments, the catheter100 may have additional hollow channels to enable fluid irrigationbefore, during and after subdural hematoma drainage. The fluid can bedirected outside the suction catheter 100, at the tip of the suctioncatheter 100 or inside the main lumen of the suction catheter 100. Fluidirrigation can decrease the viscosity of the fluid and enhance thedrainage.

In some embodiments, the fluid can deliver pharmacological agents to thetreatment location, or suspended cells and particles in a solution whichis later aspirated by the suction catheter.

In some embodiments, the lumen of the suction catheter 100 can be coatedby lubricious substances to facilitate drainage of fluid and particulatematter.

The guidance of the system can be coupled by including componentsvisible by invasive (US, CTO, Angioscopy) and non-invasive (fluoroscopy,US, CT, MR) imaging modalities. This could be coupled with image guidedinterventions. In some embodiments, the suction catheter 100 or thepenetrating element itself can be integrated with invasive imagingmodalities for structural visualization.

In some embodiments, the suction catheter 100 can include an integratedcamera for endoscopically-assisted transvascular drainage of subduralcollection. The camera can provide visualization of the advancement ofthe catheter 100 over the shaft 120 in the subdural or epidural space.The endoscope functionality can be based in optical fibers,complementary-symmetry metal-oxide-semiconductor, scanning fiberendoscope or any other methods. The optical system can be mounted in thehead of the catheter (light source and electric wire can be disposed inthe catheter wall), which can be advanced over a wire (which could bethe penetrating element) in the extravascular space and into thecollection to drain.

In some of these embodiments, the catheter 100 can have drainagefenestrations and can have a steerable mechanism to deflect the shaft ofthe catheter 100. In this embodiment, upon perforation of the arterialwall the catheter 100 is advanced co-axially.

In some embodiments, saline irrigation can be infused in the subduralspace to facilitate advancement of the catheter (e.g., to increaselubricity of the surfaces and create and separate the space) and/or forimproving direct visualization with the camera. The system can beadvanced and used to enter the collection to drain as described above.

In some embodiments, the penetrating element can have one or moreorifices in the distal segment in a range from 0.01 mm to 10 mm from thetip. The orifice can be fluidly coupled to one or more lumens of theshaft or catheter and enable irrigation upon perforation into thesubdural space.

In some embodiments, a coring element can be mounted over the balloon ofa catheter and generate a passageway through the vascular channel wall.The coring element can be in continuity with the lumen of the suctioncatheter enabling a stable passageway into the extravascular space. Insome embodiments, the balloon mounted over a catheter has a channel incontinuity to the catheter lumen. Insufflation of the balloon stabilizedthe catheter and approximates the opening of the channel to the vascularwall. Extravascular access is accomplished as previously describedherein.

In some embodiments, the MMA wall-penetrating element has a pre-shapedcurvature that it is acquired upon emergence from the delivery catheter100. In such a case, the wall-penetrating element is flexible enough tocause minimal or no deformation to the delivery catheter 100, but uponemergence into the vascular lumen it acquires a curvature that ismaintained while penetrating through the vascular wall. In someembodiments, the bending radius of the curvature may vary, and can beselected to aim the system towards the location of the target. Thisembodiment would be beneficial, for example, when the vascular geometryis divergent from the target and the penetration to the vascular wallwill not lead to the target. This diverging curvature can be combinedwith other curvatures in the shaft that only are acquired in theextravascular space. This can be achieved by modifying the bendingradius and flexibility of each individual curve.

In some embodiments, the penetrating element can have features tofacilitate penetration through the vascular wall and dura includingcutting edges, bevels, cutting tips, cone shape, coring punch, andcorkscrew shapes. Cutting features can be in the outer edge of the inneredge. The later reverse cutting edge to the inside lumen minimize thegap between two coaxial telescoping elements facilitating perforation atlower forces. Features to facilitate penetration can be one or acombination of multiple features, and it can be combined in any of thedevice elements including stylet, shaft or catheter. In someembodiments, the rigidity of the catheter 100 and/or penetrating element(e.g., shaft or micro-catheter) can be modified by air or fluidintroduction at variable pressures in accessory channels associated withthe wall of these elements. The channels can be disposed in any segmentthe catheter 100 and/or penetrating element (e.g., shaft ormicro-catheter) and can be of any length.

For example, the catheter 100 can be made stiff upon saline injection inthe wall channel to enhance the support to the penetrating element(e.g., shaft or micro-catheter) to transverse the arterial wall orsubdural membrane. Upon advancement in the extravascular space, thedistal most segment of the catheter 100 can be made flexible/soft byremoving saline solution.

In another example, the penetrating element (e.g., shaft ormicro-catheter) can have a multi-durometer construction and be stiffproximally and flexible/soft distally. The distal segment can beassociated with a channel to modify flexibility. For penetration throughthe arterial wall, the distal segment can be stiffened by fluidinjection in the inner channel. Upon vascular penetration, the innerchannel can be deflated leading to increase flexibility of thepenetrating element and save advancement. In some embodiments, thisinner channel has an opening in the distal segment that becomes occludedwhile pushing against or thorough the arterial wall. While occluded, thefluid remains inside the channel conferring maximal stiffness to thepenetrating element by positive pressure. Upon penetration into theextravascular space, the channel opening becomes un-occluded and enablesrapid release of the fluid of the inner channel leading to a decrease instiffness. This mechanism increases the safety feature of the device asdecreases the chance of brain penetration. The injection of air andfluid in these channels can be also used to deflect the catheters orpenetrating elements.

In some embodiments, the catheter 100 and or the penetrating elements(e.g., shaft 130 or micro-catheter 110) are combined with methods andmechanism to sense the extravascular position of at least of segment ofthe tube, including differential pressure, impedance, and other.

In some embodiment, one or more magnetic component can be added to anycomponent of the EVAC system for magnetic-based movement.

Upon completion of the extravascular intervention, the arteriotomy isclosed by one or a combination of the following hemostatic mechanisms:balloon, gel foam, collagen, thrombin, particles (e.g., polyvinylalcohol, embospheres), coils (e.g., pushable, injectables, detachable),liquid agents (e.g., glue, ethylene vinyl alcohol), sclerosant agents(e.g., sodium teradecyl sulfate, alcohol, algel), plugs (e.g., includingself-expandable cylindrical or hourglass shape), stitches,electrocoagulation.

In some embodiments, the hemostatic element has mechanism to preventaccidental retreat during device retrieval. As a mode of example, theseelements includes a focal enlargement on the distal segment of the gelfoam or collagen pledget and flowering elements that radially expandafter being unsheathed.

In some embodiments, at least a segment of any device subcomponents canbe detached to close the arteriotomy.

In some embodiments, the hemostatic element (like a coil) can betransected at the desired length by chemical, mechanical, and orelectrical mechanisms. This is desirable to deploy the closing elementthough the arteriotomy and then cut the hemostatic element to preventlong segments of arteries to embolize.

In some embodiments, the perforating element can be coupled with aclosure device. The closure device can be released upon removal of theperforating element at the perforation point.

In some embodiments, the arteriotomy is very small and would not resultis significant blood extravasation making the hemastatic device notneeded.

Referring to FIGS. 10-13 , an alternative embodiment of a shaft 140 hasa distal end portion with a double “J” configuration. The distal most“J” 142 can be performed can define a cutting edge or a bevel and allowsto directionally penetrate the wall of the MMA 20 or subdural hematomamembrane. Disposed in a proximal fashion, there is another “J” or “U”144 that forms after the shaft 140 emerges out from the catheter 100 andprovides an atraumatic shape for advancement into the subdural space.The distal J 142 can be sharper and stiffer than the proximal J segment144 to enhanced wall penetration. By being flexible, the proximal Jsegment becomes straightened while radially constrained within thecatheter 100. In this embodiment, no stylet is needed. Instead, thedistal J 142 tip penetrates and perforates the wall of the MMA 20. Thedistal preformed J 142 allows a directional penetration through thearterial wall by rotating the shaft 140 until it points towards andperpendicular to the subdural space. Upon penetration, the shaft 140 canbe rotated as needed to point parallel and into the subdural space andthe shaft 140 advanced outside the catheter 100 until the shaft 140acquires the shape of the proximal J 144.

Referring to FIGS. 14-16 , the depicted embodiment includes a suctioncatheter 200 and a shaft 210 that is slidably disposed within a lumendefined by the catheter 200. The catheter 200 defines drainagefenestrations in its distal tip portion.

As shown in FIG. 14 , the shaft 210 is used to perforate the wall of theMMA 20. Thereafter, the distal tip portion of the catheter 200 istapered such that, while defining a hole through which the shaft 210extends, the tip is also configured for advancement through the wall ofthe MMA 20. In addition, a distal end portion of the shaft 210 has anatural J or U shape so that (as shown in FIG. 15 ) the shaft 210provides an atraumatic tip for advancement toward the subdural hematoma10. Upon entry of the subdural hematoma 10, the shaft 210 can be pulledback and/or removed exposing the fenestrations and lumen of the suctioncatheter 200.

In some embodiments, the shaft 210 can be composed by one, two or moretelescoping elements. This design provides stiffness to penetratethrough the MMA 20 and through the subdural membranes, support toadvance into the subdural space, an atraumatic leading shape with a J orU shaft 210, and maximal vacuum efficacy when the fenestrations of thecatheter 200 are introduced into the subdural hematoma 10. Referring toFIGS. 32 and 33 , in some embodiments, the re-introduction of a shaftinto the catheter 200 can unclog a catheter 200 that is obstructed byparticulate matter. The matter can be pushed outside the catheter 200 orcompacted or macerated at the distal end of the catheter 200 byunclogging elements to allow fluid drainage through the suction catheterdistal end and/or one or a plural of side windows.

In some embodiments (FIGS. 32A-B), the distal end of the shaft has theconfiguration of a plunger, brush, arrowhead, disk, and balloon to pushthe particulate matter out. In some embodiments, (FIGS. 32C-E), theshaft has a straight or shaped configurations, such as “J”, “L”, “S”,sinusoidal, “T”, or other eccentric shapes and can move in one or acombination of linear translation, vibration, spinning, and orbiting.

In another embodiment (FIGS. 32F), the shaft has an eccentric mass atthe distal end to augment the mechanical energy delivered to agitate theparticulate matter. In addition, the eccentric configuration generatesvibration in the suction catheter and can facilitate dislodging theparticulate matter which are sticky to the inner wall of the suctioncatheter wall due to friction. The eccentric mass can also be a cuttingelement to macerate the particulate matter.

In alternative embodiments (FIGS. 32G), the shaft distal end has anexpandable element, which can be expanded manually such as inflating aballoon or opening a stent, or self-expand due to centripetal forceunder rotational motion. This expandable element can augment themechanical energy delivered to agitate the particulate matter and canalso have a cutting feature to macerate the particulate matter. Inanother embodiment (FIG. 32H) the shaft is an impeller, auger, or anArchimedes screw to facilitate transportation of the fluid orparticulate matter into and outside the suction catheter.

The unclogging elements can be enclosed within the suction catheter toremove the particulate matter and fluid that are already pulled into thesuction catheter by vacuum. In some embodiments, the unclogging elementscan be extended to be flush with or beyond the distal end of the suctioncatheter. In some embodiments, the unclogging elements become largerupon emergence from the distal end of the suction catheter. Theunclogging elements can be constructed with a memory material (e.g.,shape-memory alloy) such as copper-aluminum-nickel and nickel-titanium(nitinol) or actuation by centripetal force due to rotation. For theunclogging elements to be deployed outside the suction catheter, thecutting element can be configured to macerate the clot but not damagethe brain or dural surface by having the cutting edges enclosed andblinded to the brain or dural surface but allows contact with theparticulate matter (FIG. 32I).

The shaft with such features are longitudinally extended though theextraction device including the suction catheter. The unclogging elementfacilitates hematoma evacuation and contains the above featurespreferentially in the distal end of the subcomponent, e.g., within 5 cmfrom the distal end. The proximal end of the unclogging elements can beattached to a drive unit including an aspiration pump and an electricalmotor capable of providing a rotational speed to the unclogging elementin a range from 50 rpm to 500,000 rpm.

In other embodiments, the unclogging elements can be actuated by hand toachieve a rotational speed in a range from 1 rpm to 100 rpm. In someembodiments, a fitting assembly of the unclogging elements providesmovement of the macerating element relative to the suction catheter. Thefitting assembly can include a Luer assembly or a Touhy-Borst valve tomaintain a seal around the unclogging element or a surrounding hypotube.

In some embodiments, the shaft is tapered to minimize the occupation ofthe suctional lumen of the suction catheter and to maximize the suctionand suctional flow. In some embodiments, drugs are infused through oneor a plural of lumens in this catheter system to facilitate dissolvingthe particulate matter. In some embodiments, drugs are infused throughone or a plural of lumens in this catheter system to lubricate theinterfaces between the particulate matter and the suction catheter andthe shaft to help the particulate matters to flow proximal along thesuction catheter. In some embodiments, fluids are injected to dilute thefluid to be drained.

Referring to FIG. 33A, in some embodiments, the distal end of thesuction catheter, e.g., the portion of the suction catheter within 5 cmfrom the distal end, wall is expandable to increase the opening area ofthe suction catheter. The suction force is proportional to the cathetercross-sectional area and the suctional flow is proportional to thesquare of the catheter cross-sectional area. Increasing the opening areaincreases the suction force and flow.

In one embodiment, the distal end of the suction catheter is constructedwith a polymer jacket with low elasticity and high stretch limit (e.g.,such as thermoplastic polyurethane, or silicone). After the suctioncatheter is delivered to the target, a stent is delivered to the distalend of the suction catheter and opened to deform the polymer jacket.

In an alternative embodiment, the distal end of the suction catheter ismade by shape memory alloy, such as copper-aluminum-nickel andnickel-titanium (nitinol) pre-configured during manufacturing to havethe expanded funnel shape. The shape memory alloy funnel is attached byone or a plural of pull wires extending from the distal end to theproximal end of the suction catheter. Before activating expansion, thepull wires are pulled to compress the funnel to a cylindrical shape.After the suction catheter reaches target, the pull wires are releasedto let the shape memory alloy bounce back to take the funnel shape.

In some embodiments, the distal end of the suction catheter can beconstructed by materials with high thermal-expansion coefficient. Heatis generated and conducted to this segment, e.g., using one or moreelectrical resistance wire inside the suction catheter wall or anotheraccessory lumen, to activate expansion. To deactivate expansion, coldfluid such as saline is transmitted through the lumen of the catheter tocool down the distal end of the suction catheter and restore thecylindrical shape.

Referring to FIG. 33B, in another embodiment, high-pressure fluid (e.g.,saline) can be delivered through a lumen inside the suction catheterwall or a separate lumen adjacent to the suction catheter from a fluidsource and enters the suction catheter lumen at or near the distal endthrough one or a plural of flow injection ports on the inner wall of thesuction catheter. This high-pressure flow jet is beneficial as it canmacerate the particulate matter inside the suction catheter and alsopush the fragments of the particulate matter towards the proximal end ofthe suction end. The flow injection port is oriented so that the flowjet is preferably inclined towards the proximal end of the suctioncatheter or perpendicular to the long axis of the suction catheter toprevent high pressure flow entering the subdural space. The flowinjection pattern can be continuous or pulsed.

In some embodiments, the suction catheter and/or the fitting assemblymay have valves to ensure unidirectional flow of fluid away from thesubdural space.

In some embodiments, the distal segment of the suction catheter 100 caninclude wire baskets, balloons, and other elements to preventparticulate matter to clog the suction catheter 100. In someembodiments, the suction catheter 100 can be funnel shaped or equippedwith an expandable funnel shaped balloon to enhance fluid and thrombusremoval. In some embodiments, a funnel can be created by unsheathing ahypotube with a plurality of cuts or braided stent. In some embodiments,the funnel skeleton can be covered by polymers to be fluidly coupled tothe suction catheter.

In some embodiments, the suction catheter 100 can be equipped with aballoon proximal to the distal end. The insufflation of the balloonafter entry to the subdural space can be advantageous to preventbleeding, prevent kickback back into the artery, enhance the pushabilityof the shaft 120, and atraumatically push the brain expanding thesubdural space. In some embodiments, a shaped balloon at the distalsegment of the suction catheter 100 could direct the opening to thecatheter to be parallel to the brain and dura into the subdural space.

Bleeding may occur in the extravascular space from the same vesselharboring the device or from other vessels. To reduce bleeding or toachieve hemostasis, in some embodiments, one or more subcomponentsinclude cauterization devices and methods including electrocautery,chemical cautery, laser, ultrasonic cautery and balloon.

Referring to FIGS. 17 and 18 , in some embodiments, the penetratingelement 310 (e.g., shaft or micro-catheter) can be diverged laterally bya diverging surface of the lumen of the catheter 300. In thisembodiment, the diverging surface is disposed at or close the outlet ofthe catheter 300. The angle of the surface in reference to the main axisof the lumen of the catheter 300 where the penetrating element 310 isdisposed will define the angle of which the penetrating element 310 willproject upon emergence from the delivery catheter 300.

In some embodiments, the suction catheter 100 or venous delivery sheathcan be equipped by balloons or stents to anchor the device to thevascular wall and facilitate directional penetration. This would bebeneficial when veins and dural venous sinuses are used to navigate intothe intracranial compartment and drain fluid, particular matter orclots.

The invention disclosed herein teaches access into the intraduralcompartment and drainage of SDH though the venous system. In particular,the SSS and the junction of the SPS 13 to the transverse-sigmoid sinus12 have anatomical features that make them suitable to access to thesupratentorial subdural space where SDH are typically located.

In some embodiments, a venous delivery sheath can be navigated from aperipheral venous access into the jugular vein, the sigmoid andtransverse sinuses and into the superior sagittal sinus. At that point,the venous delivery sheath can be articulated by any of the embodimentsdescribed herein (for example a pull wire) to anchor the catheter in thevenous system and direct the distal end towards the lateral wall of thesinus ipsilateral to the collection to drain. The shape of the SSS istriangular with the largest side being the base oriented against theskull. The articulation of the delivery sheath self-orients the deviceat the base of the triangle (e.g., the skull) and orients the distal endof the device to the lateral wall of the sinus and providesdirectionality to the perforation elements towards the subdural space.

In some embodiments, directionality and anchoring can be also achievedby deployment of a stent or insufflation of a balloon. At this point,the dural sinus wall can be penetrated by a shaft 120 or an orificecreated by thermoablation, coring punch or any embodiment describedherein. Then, access to the extravascular space can be obtained anddevices navigated from the catheter into the extravascular space,including a suction catheter 100 for drainage of fluid, thrombus andparticulate matter. After completion of the intervention in theextravascular space, the device is pulled back into the vascular channeland the orifice closed by a covered stent or any of the embodimentsdescribed herein.

In some embodiments, the sheath distal OD is less than 0.118″ tonavigate into the SSS in >90% of patients. The length is 130 cm toenable trans-femoral vein approach. The sheath has a flexibilityallowing the subcomponents to advance through a curve angle of 90° ormore to enter the intracranial compartment through the jugular bulb andtransverse the transverse-sigmoid junction and the torcula.

The sheath flexibility can achieve a uni-directional deflection havingcurve angle greater than 90° to direct the inner perforating element tothe lateral wall of the sinus and provide distal support.

In some embodiments, the catheter has a distal ID less than 0.070″ tofacilitate clot ingestion, and a length of 140 cm for trans-femoral use.The catheter is sufficiently stiff to generate 6N of forward loadwithout kinking and ovalizing to perforate SSS/dura and resistaspiration pressures of greater than 20 inHg without collapsing toaspirate cSDH with syringe.

In some embodiments, the catheter has sufficient flexibility to achievebidirectional deflection to swipe the subdural space and ingest SDH andcapable of advancing though a minimal curve angle of at least 90°.

In some embodiments, the trocar is compatible with off-the-shelf 0.035″wires to be advanced over a wire into SSS. The trocar has a distal OD ofless than 0.004″ smaller than an enveloping catheter's ID to avoidcatching the dura. The trocar includes a sharp beveled tip and iscapable of generating at least 6N of forward load without kinking forSSS wall and dura perforation. The trocar is able to advance thoughminimal curve angle of 90°.

In some embodiments, the plug has a diameter compatible with deliverythrough the catheter (e.g., an OD less than the catheter ID) and iscapable of achieving a minimal curve angle of 90°. The plug is pushableor detachable for durotomy closure with patency of the SSS. Thesubcomponents need to be radio-opaque or have fluorscopic elements.

FIGS. 34A through 34E are schematic illustrations depicting the use ofan embodiment to access the subdural space though the wall of the SSSand drain SDH. Each illustration includes a coronal cross section on theSSS and left parasagittal space, and an oblique view of a 3Dreconstruction on the left sigmoid sinus. In FIG. 34A, the deliverysheath distal access sheath and catheter are advanced over a wire intothe SSS from the femoral vein.

The wire is removed and roadmap venogram is performed (e.g., injectingcontrast in the SSS or from the arterial size if there is a catheter inthe artery introduced for diagnostic purposes) to select a vein-freesegment of the sinus for perforation.

FIG. 34B shows the trocar is coaxially advanced to the distal end of thecatheter and the sheath is articulated to provide stability, stiffnessand proximal support to the system, and to direct the perforatingelement to the lateral wall of the sinus. The trocar is then pushedforward to gain access through the sinus wall and dura into theparasagittal subdural space.

FIG. 34C shows wire advanced over the trocar for safe subduralnavigation and the catheter is advanced coaxially through the durotomysite into the subdural space over and beyond the trocar. The trocar isremoved and the catheter is connected to a vacuum source and articulatedanteriorly or posteriorly to swipe the subdural space.

In embodiments in which enhanced evacuation of fluid and clots (e.g., anSDH) is needed, an auger shaft (or a rotational element, or avibrational element, or any macerating elements described herein) isadvanced to the distal end of the catheter and actuated with concurrentvacuum as shown in FIG. 34D.

FIG. 34E shows the catheter system is removed and a hemostatic closureelement is deployed at the durotomy site after completion of drainage.

FIGS. 35A through 34C are schematic illustrations depicting the use ofan embodiment in which a venous delivery sheath is navigated from aperipheral venous access into the jugular vein and then advancedintracranially into the sigmoid-transverse junction. This can befacilitated by advancing the venous delivery sheath over a standardglidewire and a catheter (for example Sofia 5F or 6F, Microvention). Atthat point, the venous delivery sheath can be oriented and stabilized byleveraging the anatomy of the region including the SPS.

The venous complex formed by the transverse sigmoid junction and the SPSprovide has features enabling safe and effective perforation. Forexample, these features include but are not limited to an SPS is presentand communicates with the transverse sinus in 97% of patients, enablingtrans jugular approaches into the intracranial space; a highly stableposition of the SPS between a bony groove and the thick dural tentoriumproviding ideal place to introduce or deploy an element to anchor andorient the device; the SPS connects at or close to roof the transversesinus which faces the supratentorial compartment; most of the SDH willbe transected if the transvascular perforation and subdural spacenavigation is done at an angle of 100 degrees from the longitudinal axisof the SPS; the large lumen of the sigmoid-transverse junction enablingaccess with large bore device for evacuation of thicker fluid or stifferclots and for delivery of larger devices to the intradural compartment;very close topographic proximity to the cerebral convexity in thesupratentorial compartment where the SDH are located.

In some embodiments, as shown in FIGS. 35 and 36 , the venous deliverysheath has an annex (extension of the sheath, catheter, wire, stent, andballoon) that can be advanced over a wire in the SPS. The annex canorient the venous delivery sheath and provide support while preventingkickback during penetration. In the embodiments with a balloon, theballoon can be at the tip of a microcatheter or a wire. In theembodiments with stents, the stent can be deployed through amicrocatheter and remained mechanically attached to a wire.

The wire can be round, square, rectangular or any other shape and isattached to the anchoring element distally which is within the SPS. Theperforating element can be advanced over the wire to the distal end ofthe venous delivery sheath. In some embodiments, the perforating elementis a hollow structure with a cutting bevel (needle or catheter) which isadvanced over a wire (including in a rapid exchange system).

The rail between the wire and the penetrating element is at least in adistal segment of the perforating element but not at the most distalsegment of the perforating element. This embodiment limits thepenetration depth into the intradural compartment. The distance betweenthe distal end of the perforating element and the distal most apertureof the rail system where the wire enters the perforating system minusthe wall thickness of the sinus results in the penetration depth. Thissystem is advantageous as orients the perforation element, providesdistal support (by providing tension to rail system by pulling on theanchoring element while pushing forward the penetrating element) andlimits the depth of perforation.

Referring to FIGS. 37A through 37C, in some embodiments, the rail systemcan be formed by the anchor element and wire and a protective sheath.The protective sheath may be beneficial to prevent catching of theperforating element during advancement inside the venous delivery sheaththough the normal anatomical tortuosity of the sigmoid sinus and jugularbulb. Referring to FIG. 37A, in such embodiments, the perforatingelement covered by the protective sheath is advanced to the distal endof the venous delivery sheath. Referring to FIG. 37B, the protectivesheath is pulled back over the anchor wire exposing the penetratingelement. Referring to FIG. 37C, the penetrating element is advancedthough the sinus wall.

In another embodiment, the protective sheath is advanced to the distalend of the venous delivery sheath, and the penetrating element pushedforward to protrude outside the protective sheath and perforate thesinus wall. In some embodiments, the protective sheath is translatedlongitudinally by pull or push wires actuated by a knob or wheel in ahandle assembly.

In other embodiments, the venous delivery sheath has one or more balloonelements to anchor the sheath to the sinus wall. Balloon elements can besingle, multiple, located in the same subcomponent segment or inmultiple subcomponent segments, and can be occlusive or non-occlusive.

In some embodiments, a balloon can be insufflated at the distal segmentof the venous delivery sheath within the distal sigmoid sinus. Aperforating element can be advanced under fluoroscopic guidance thoughthe sinus wall.

The lumen of the perforating element provides a channel to inject salinesolution or other lubricious substance in the subdural space, contrastto confirm the subdural location of the perforating element, and/or awire and suction catheters to navigate into the subdural space and drainthe SDH. The perforating element provides a path to introduce otherdevices and diagnostic or therapeutic matter.

In some embodiments, after gaining extravascular access, one or moreimplant elements can be placed, fully or partially, in the extravascularspace temporarily or permanently (e.g., long-term implants). Implantelements can include electrodes, sensors, transmitter, receivers, grids,ports, catheters (associated with valves and anti-syphon mechanisms),biopsy needles or punches, implantable chemotherapy wafers or radiationseeds.

The perforating element is retracted before, during or after securinghemostasis at the perforation point by a hemostatic element, the anchorelement recaptured by advancing a microcatheter and re-sheathing thestent, of deflating the balloon, or pulling back the wire or annex.

The perforation point through the wall of a sinus can be closed by thehemostatic agents previously described, including but not limited to gelfoam, collagen, plugs, stitches. Plugs include self-expandable nitinolbraid with cylindrical or hourglass shape, or one or more disks orlobes. Detachment of hemostatic agents can be electrochemical,electromechanical, mechanical, rotation of screw attached. In mostembodiments for closure of perforation at the sinus wall the sinus mainlumen remains open.

In some embodiments, the hemostatic element has a mechanism to preventaccidental (e.g., unintentional) retreat during device retrieval. As anexample, these elements includes a focal enlargement on the distalsegment of the gel foam or collagen pledget and flowering elements thatradially expand after being unsheathed. FIGS. 38A through 38D areschematic illustration depicting an embodiment in which a plug isdelivered though a plug delivery catheter. In FIG. 38A, the plug elementis advanced though the needle into the extravascular space. In FIG. 38B,the distal plug element is unsheathed and expands as a disk or aparachute.

Referring to FIG. 38C, the plug element is mechanically connected by awire which is pulled to ensure good apposition against the subdural sideof the sinus. In FIG. 38D, the plug element delivery catheter isunsheathed and deploys the proximal plug element, which is then pushedforward to ensure good apposition against the intravascular side of thesinus.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of anyinvention or of what may be claimed, but rather as descriptions offeatures that may be specific to particular embodiments of particularinventions. Certain features that are described in this specification inthe context of separate embodiments can also be implemented incombination in a single embodiment. Conversely, various features thatare described in the context of a single embodiment can also beimplemented in multiple embodiments separately or in any suitablesubcombination. Moreover, although features may be described herein asacting in certain combinations and even initially claimed as such, oneor more features from a claimed combination can in some cases be excisedfrom the combination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. In certain circumstances, multitasking and parallel processingmay be advantageous. Moreover, the separation of various system modulesand components in the embodiments described herein should not beunderstood as requiring such separation in all embodiments, and itshould be understood that the described program components and systemscan generally be integrated together in a single product or packagedinto multiple products.

Particular embodiments of the subject matter have been described. Otherembodiments are within the scope of the following claims. For example,the actions recited in the claims can be performed in a different orderand still achieve desirable results. As one example, the processesdepicted in the accompanying figures do not necessarily require theparticular order shown, or sequential order, to achieve desirableresults. In certain implementations, multitasking and parallelprocessing may be advantageous. In addition, figures representingembodiments including variations which facilitate the identification andfunction of each device subcomponents.

What is claimed is:
 1. An apparatus, comprising: a catheter having aproximal end and a distal end and defining a lumen therebetween, thedistal end of the catheter configured to be disposed within anintracranial blood vessel of a subject; and a shaft slidably disposedwithin the lumen, the shaft including a distal tip portion configured tobe advanced distal to the distal end of the catheter, the distal tipportion including a perforating element configured to penetrate througha wall of the blood vessel and dura to be disposed in an extravascularspace, the distal tip portion of the shaft configured to transition froma radially constrained configuration in which the perforating element isdistally positioned to penetrate through the wall of the blood vesseland the dura to a curved configuration when unconstrained in theextravascular space.
 2. The apparatus of claim 1, wherein the catheteris configured to be advanced over at least a portion of the shaft andinto the extravascular space, the catheter further configured to coupleto a vacuum source that can apply a vacuum to the lumen to remove fluidsand matter from the extravascular space.
 3. The apparatus of claim 1,wherein the atraumatic shape is a J shape or a U shape.
 4. The apparatusof claim 1, wherein the perforating element includes an energy elementconfigured to generate ablation energy to penetrate through the wall ofthe blood vessel and the dura.
 5. The apparatus of claim 1, wherein aportion the perforating element has a non-circular cross-sectionalshape.
 6. The apparatus of claim 1, wherein the perforating elementincludes a cutting bevel configured to penetrate through the wall of theblood vessel and the dura.
 7. The apparatus of claim 1, wherein theblood vessel is the middle meningeal artery, and the penetrating elementis configured to penetrate through the wall of the middle meningealartery (MMA) and the dura and reach the intracranial extravascularspace.
 8. The apparatus of claim 1, further comprising a hemostaticelement configured to close an arteriotomy in the blood vessel formed bythe penetrating element, the catheter being configured to deliver thehemostatic element to close the arteriotomy.
 9. An apparatus,comprising: a catheter having a proximal end and a distal end anddefining a lumen therebetween, the distal end of the catheter configuredto be disposed within a blood vessel of a subject; a shaft slidablydisposed within the lumen, the shaft including a distal tip portionconfigured to be advanced distal to the distal end of the catheter; andan energy element disposed at a distal end of the distal tip portion,the energy element configured to generate radiofrequency (RF) energy topenetrate through a wall of the blood vessel and dura, after the energyelement has penetrated through the wall of the blood vessel and thedura, the distal tip portion of the shaft and the distal end of thecatheter configured to be positioned in an intracranial extravascularspace, the proximal end of the catheter being configured to couple to avacuum source that can apply a vacuum to the lumen to remove fluids andmatter from the extravascular space.
 10. The apparatus of claim 9,wherein the distal tip portion of the shaft is configured to transitionfrom a radially constrained configuration in which the energy element isdistally positioned to generate RF energy to penetrate through the wallof the blood vessel and the dura to a curved configuration in which theenergy element is curved back toward the shaft.
 11. The apparatus ofclaim 9, wherein the energy element includes a single electrodeconfigured to generate the RF energy.
 12. The apparatus of claim 9,wherein the energy element includes two or more electrodes configured togenerate the RF energy in a monopolar or bipolar mode.
 13. The apparatusof claim 9, further comprising a temperature sensor disposed on thedistal tip portion of the shaft and configured to monitor a temperatureof tissue at or near a site of the penetration.
 14. The apparatus ofclaim 9, further comprising one or more electrodes configured to monitoran impedance or a permittivity value of tissue and fluids.
 15. Theapparatus of claim 9, further comprising a pressure sensor disposed onthe distal tip portion of the shaft and configured to monitor at leastone of: a contact pressure between the energy element and tissue, or apressure of fluid surrounding the energy element.
 16. The apparatus ofclaim 9, wherein the blood vessel is the middle meningeal artery, andthe energy element is configured to penetrate through the wall of themiddle meningeal artery (MMA) and the dura and reach the intracranialextravascular space.
 17. The apparatus of claim 9, wherein the bloodvessel is the middle meningeal artery, and the energy element isconfigured to deliver RF energy to close a transvascular passageway anda vascular lumen of the MMA and obtain hemostasis.
 18. The apparatus ofclaim 9, wherein the catheter is further configured to deliver one ormore of: a device, a therapeutic agent, or a fluid into theextravascular space.
 19. A system, comprising: a radiofrequency (RF)generator configured to generate RF energy; a RF device including adistal portion including an energy element, the energy elementconfigured to be operatively coupled to the RF generator to receive theRF energy and to apply the RF energy to penetrate through a wall of ablood vessel and dura of a subject, the distal portion of the RFablation device configured to be advanced extravascularly after theenergy element has penetrated through the wall of the blood vessel andthe dura; and an aspiration catheter defining a lumen, the aspirationcatheter configured to be advanced over at least a portion of the RFdevice and into the extravascular intracranial space.
 20. The system ofclaim 19, wherein the proximal end of the catheter is configured tocouple to a vacuum source that can apply a vacuum to the lumen to removethe fluids and matter from the extravascular space.
 21. The system ofclaim 19, wherein the RF generator is configured to generate the RFenergy in the form of a pulse waveform including a series of RF pulses.22. The system of claim 21, further comprising a temperature sensordisposed at or near the distal portion of the RF ablation device andconfigured to monitor a temperature of tissue at or near a site of thepenetration, the RF generator configured to modulate one or moreparameters of the pulse waveform based on a temperature signal receivedfrom the temperature sensor.
 23. The system of claim 21, furthercomprising one or more electrodes configured to monitor an impedance ora permittivity value of tissue and fluids, the RF generator configuredto modulate one or more parameters of the pulse waveform based on theimpedance or the permittivity value received from the one or moreelectrodes.
 24. The system of claim 23, wherein the one or moreparameters include at least one of: a duration, a voltage magnitude, aduty cycle, or a pulse width of the pulses of RF energy.
 25. The systemof claim 19, further comprising a pressure sensor disposed at or nearthe distal portion of the RF ablation device and configured to monitorat least one of: a contact pressure between the energy element andtissue, or a pressure of fluid surrounding the energy element, the RFgenerator configured to activate the generation of the RF energy or toterminate generation of the RF energy based on a pressure signalreceived from the pressure sensor.
 26. The system of claim 19, whereinthe energy element includes a single electrode configured to apply theRF energy in a monopolar mode.
 27. The system of claim 19, wherein theenergy element includes two or more electrodes configured to apply theRF energy in a monopolar or bipolar mode.
 28. A method, comprising:extending a distal tip portion of a shaft disposed within a lumen of acatheter distal to a distal end of the catheter, the distal end of thecatheter being disposed within an intracranial vessel of a subject;creating an opening in a wall of the vessel and dura using a penetratingelement disposed on the distal tip portion of the shaft; advancing thedistal tip portion of the shaft into the extravascular space and towarda subdural hematoma, the distal tip portion of the shaft acquiring acurve when unconstrained in the extravascular space; and advancing thecatheter over at least a portion of the shaft and into the subduralhematoma; and applying suction to the lumen of the catheter to removefluid from the subdural hematoma after the catheter is positioned withinthe subdural hematoma and the shaft removed.
 29. The method of claim 28,further comprising, after applying suction to remove the fluid from thesubdural hematoma: retracting the catheter back toward the openingcreated in the wall of the artery; and delivering, via the lumen of thesuction catheter, a hemostatic element or a radiofrequency device toclose the opening or vascular lumen.
 30. The method of claim 28, furthercomprising injecting, using the catheter, an embolic material toembolize an artery to prevent further development of the subduralhematoma.